View from The Hill: Now Scott Morrison’s ‘preference’ is for net zero emissions by 2050


Michelle Grattan, University of Canberra

Scott Morrison has taken another, albeit very small, step towards endorsing a target of net zero emissions by 2050.

He told the National Press Club on Monday: “Our goal is to reach net zero emissions as soon as possible, and preferably by 2050”.

This follows his previous wording of wanting net zero “as quickly as possible”.

It remains unclear whether the baby steps will lead to his embracing the 2050 target later this year. But he’d almost certainly like to do so – it would undoubtedly smooth the way with the Biden administration as well as putting Australia in a better position for the Glasgow climate conference in November.

But there are pesky Nationals (and a few others) ready to make the road rocky.

The next climate test for Morrison is President Biden’s planned leaders’ climate summit on Earth Day, April 22.

Climate is at the centre of the Biden agenda, which makes the April summit particularly important.

The President’s climate envoy John Kerry told a White House press briefing last week: “the convening of … this summit is essential to ensuring that 2021 is going to be the year that really makes up for the lost time of the last four years and that the U.N. Climate Conference — COP26, as it’s called, which the UK is hosting in November — to make sure that it is an unqualified success”.

Kerry spoke to energy minister Angus Taylor last week when, according to the Australia readout of the discussion, Kerry “welcomed Australia’s commitment to achieving net zero emissions as soon as possible”.

As, perhaps, one might welcome an infant’s early progress.

Asked on Monday whether he expected to attend the Biden climate conference, Morrison replied cautiously, on the basis of lack of information.

Perhaps he didn’t want to take any risks. In December he was embarrassed when an expected invitation to a speaking spot at the “climate ambition summit” hosted by Britain, France and the United Nations didn’t eventuate. Australia was judged as not having sufficient “ambition” to warrant a slot.

“ At this stage, we haven’t received the details or nature of the event,” Morrison said of the April gathering.

“As you can appreciate, things are very busy over in the White House at the moment.”

When details were received, “then I’m sure the Minister for Foreign Affairs, Marise Payne and I, and Angus Taylor, and others, will discuss what is the best way for us to participate in that and how that will work.

“But we welcome it and we look forward to supporting it.”

Maybe there’ll be more to know when Morrison speaks to Biden. As of Monday, the PM was still waiting fot his first post-inauguration call from the President (they spoke after the election). The Prime Minister’s Office could only say the call was expected “within coming days”.

Morrison on Monday repeated strongly his mantra of advancing climate policy by “technology” not “tax”.

If he does move to the 2050 target, the rationale he will give for the shift will be the progress of technology.

“My commitment to Australians that I will not tax our way to net zero by 2050 is a very, very important one and I will hold my faith with the Australian people on those issues. So we will see how the technology develops,” he said.

If he wished, he obviously could use “technology” at any point as his cover for changing his position. The issue will be if and when he thinks he has the political cover.The Conversation

Michelle Grattan, Professorial Fellow, University of Canberra

This article is republished from The Conversation under a Creative Commons license. Read the original article.

An unexpected consequence of climate change: heatwaves kill plant pests and save our favourite giant trees



Shutterstock

Gregory Moore, University of Melbourne

Australia is sweltering through another heatwave, and there will be more in the near future as climate change brings hotter, drier weather. In some parts of Australia, the number of days above 40℃ will double by 2090, and with it the tragedy of more heat-related deaths.

In the complex world of plant ecology, however, heatwaves aren’t always a bad thing. Rolling days of scorching temperatures can kill off plant pests, such as elm beetles and mistletoe, and even keep their numbers down for years.

This is what we saw after the 2009 heatwave that reached a record 46.4℃ in Melbourne and culminated in the catastrophic Black Saturday bushfires. Years later, the trees under threat from the pest species were thriving. Here are a few of our observations.

Saving red gums from mistletoe

In the days following Black Saturday, botanists, horticulturists and arborists noticed a curious heatwave side-effect: the foliage of native Australian mistletoes (Amyema miquelii and A. pendula species) growing on river red gums lost their green colour and turned grey.

The two species of mistletoe are important in the ecology of plant communities and to native bird and insect species. But infestation on older trees can lead to their deaths, particularly in drought years.

Australian mistletoe is not related to the northern hemisphere mistletoes of Christmas kissing fame. They are water and nutrient parasites on their host tree and can kill host tissues through excessive water loss.

A eucalyptus tree trunk covered in leaves on a dried brown grass
The native mistletoe, Amyema miquelii, strangles this eucalyptus coolabah in the Burke River floodplain.
John Robert McPherson/Wikimedia, CC BY-SA

Often mistletoes go largely unnoticed, only becoming obvious when they flower. This is because many have evolved foliage with a superficial resemblance to the host species, a phenomenon known as host mimicry or “crypsis”.

During the Black Saturday heatwave, many mistletoes growing on river red gums died. The gums not only survived, but when record rains came in 2010, they thrived. A decade on, the mistletoe numbers are gradually increasing, but they’re still not high enough to threaten the survival of older, significant red gums.




Read more:
The world endured 2 extra heatwave days per decade since 1950 – but the worst is yet to come


We want both mistletoes and red gums to persist. But often the old red gums are last survivors of larger populations that have been cleared — a seed source for future regeneration.

Under-appreciated elms

In many parts of Australia, the exotic English and Dutch elms are important parts of the landscapes of cities and regional towns. Elms provide great shade, are resilient and often low-maintenance. They also provide important environmental services, such as nesting sites for native mammals and birds.

Indeed, as Dutch elm disease decimates elm populations across North America and Europe, Australia can claim to have many of the largest elms and the grandest elm avenues and boulevards in the world, which we often under-appreciate.

A street lined by tall elms
Australia is home to some of the most beautiful elm avenues in the world.
denisbin/Flickr, CC BY-ND

But sadly, over the past 30 years the grazing of the elm leaf beetle, Xanthogaleruca luteola, has threatened the grandeur of our elms. These beetles can strip leaves to mere skeletons, and while the damage doesn’t usually kill the tree, it can make them look unsightly.

On Black Saturday, tens of thousands of elm leaf beetles fell from trees after prolonged exposure to high temperature. So many died, they formed what looked like a shadow under the tree canopies. Beetle numbers remained low for at least five years after that.




Read more:
Why there’s a lot more to love about jacarandas than just their purple flowers


Control programs, which often involve spraying chemical pesticides, were not required in that five year period. This was good for the environment as the chemicals can affect non-target sites and species. And we calculated that this saved well over A$2 million for Melbourne alone, money that could be better spent on parks and gardens (and of course, the elms looked splendid!).

Our iconic Moreton Bay figs

Then there are our magnificent, iconic Moreton Bay figs (Ficus macrophylla). Their large, glossy leaves, huge trunks, veils of aerial roots and massive canopies spread for more than 40 metres, and make them an Australian favourite.

Moreton Bay figs are prone to insect infestations of the psyllid, Mycopsylla fici, which can seriously defoliate trees under certain conditions. The fallen leaves can also stick to the shoes of pedestrians, causing a slipping hazard.

In Melbourne, psyllid numbers that were high before Black Saturday fell to undetectable levels in the following month.

Once again, a heatwave and hot windy weather had done an unexpected service. The incidence of psyllids has remained low for a decade or more now and, as with elm leaf beetles, control measures proved unnecessary and money was saved.

An enromous Moreton Bay fig trunk in a park
Moreton Bay figs are prone to insect infestations.
Shutterstock

Winners and losers

Many urban trees are renowned for their resilience to stress, both natural and human-caused. Climate change is proving a significant stress to be overcome, but we’ve observed how the stress can affect pests and disease species more than their hosts.

This gives the species growing in very tough urban conditions, where they lack space and are often deprived of water and good soils, a slight advantage, which may be the difference between living and dying under climate change.




Read more:
Tree ferns are older than dinosaurs. And that’s not even the most interesting thing about them


Climate change is bringing far more losses than gains. But, occasionally, there will be wins, and those managing pests in our urban forests must take advantage when they present.

If insect pest numbers fall we can direct resources to establishing more trees and ensuring our trees are healthier. The best way to avoid pests and diseases attacking trees is by providing the best possible growing conditions. That way we avoid problems before they arise rather than treating symptoms.

So as you swelter during this heatwave, remember it may not be all bad news for our urban and natural environments. Sometimes, positive outcomes arise when and where we least expect them.




Read more:
As heatwaves become more extreme, which jobs are riskiest?


The Conversation


Gregory Moore, Doctor of Botany, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Burnt ancient nutshells reveal the story of climate change at Kakadu — now drier than ever before



S. Anna Florin., Author provided

S. Anna Florin, University of Wollongong; Andrew Fairbairn, The University of Queensland; Chris Clarkson, The University of Queensland; James Shulmeister, University of Canterbury; Nicholas R Patton, University of Canterbury, and Patrick Roberts, Max Planck Institute for the Science of Human History

Archaeological research provides a long-term perspective on how humans survived various environmental conditions over tens of thousands of years.

In a paper published today in Nature Ecology and Evolution, we’ve tracked rainfall in northern Australia’s Kakadu region over the past 65,000 years. We wanted to know how major changes in rainfall may have affected the region’s Aboriginal communities through time.

Our findings suggest the Kakadu region wasn’t as prone to dry spells as surrounding areas — and it likely functioned as a place of refuge for early Australians as they struggled through harsh and arid conditions.

Learning lessons from leftovers

To generate a rainfall record spanning 65,000 years, we used ancient food waste left behind by the First Australians living at Madjedbebe, a rock shelter on Mirarr country in the Kakadu region.

This site boasts the earliest known evidence of humans living in Australia. It also boasts plenty of Pandanus spiralis, a native plant commonly called “pandanus” or “screw pine”.

This plant, known as “anyakngarra” to the Mirarr people — the Traditional Owners of Madjedbebe — is very important to them.

Anyakngarra fruit grows on a tree.
Anyakngarra (Pandanus spiralis) fruit. The tree is native to northern Australia and ubiquitous around the Top End’s waterholes and floodplains.
Author provided

Its leaves are used for weaving, its trunk to create dye, its fruit flesh is used in a drink and its nuts (the seed kernels within the fruit) are consumed as a rich source of fat and protein.

Anyakngarra’s nuts were also eaten by the First Australians 65,000 years ago. Discarded nut shells have been preserved as burned fragments, disposed of in fireplaces over time.

These small remnants have proven hugely useful for our research team, which includes archaeologists, environmental scientists and Traditional Owners.




Read more:
65,000-year-old plant remains show the earliest Australians spent plenty of time cooking


In a nutshell

By analysing the isotopic composition in ancient anyakngarra nutshells, we could track rainfall at Madjedbebe. Specifically, we detected how much water (and therefore rainfall) was available to anyakngarra plants in the past.

This analysis is possible due to photosynthesis – the process by which plants convert carbon dioxide in the air into sugars. Anyakngarra plants absorb two isotopes of carbon from the atmosphere: ¹²C and ¹³C. Isotopes are different types of atoms within a chemical element that have the same number of protons but a different number of neutrons. Chemically, the isotopes of carbon are the same, but each has a different atomic “weight”.




Read more:
Explainer: what is an isotope?


When environmental conditions are favourable, an anyakngarra plant will preferentially absorb more ¹²C than ¹³C. But if a plant is stressed by its environment, such as when it’s waterlogged due to seasonal flooding, it begins to absorb more ¹³C.

The isotopic composition (the ratio of ¹²C to ¹³C) is recorded in the sugars used by the plant for new tissue growth, including for the seasonal growth of nuts.

A higher proportion of ¹³C in a nutshell indicates that the plant it came from was waterlogged during its growth season. From this, we can conclude it likely experienced higher levels of rainfall.

Anyakngarra fruit.
Pictured is the anyakngarra fruit, which has a fleshy section (now dried and fibrous) a hard nutshell and multiple white seeds (or nuts) inside.
Author provided

Like an oasis in a desert

Over the past 72,000 years, humans have lived through an ice age in which there were two particularly cold periods called “stadials”. During stadials, glaciers extended to cover parts of North America, northern Europe, northern Asia and Patagonia (in South America).

The height of the second stadial in this ice age was called the Last Glacial Maximum. While this occurred 22,000 to 18,000 years ago, intense cold and dry conditions in Australia started as early as 30,000 years ago.

During this time, water availability was the main challenge in arid northern Australia (rather than low temperatures). The country’s arid zone expanded dramatically and parts of central Australia may have been temporarily abandoned by Aboriginal people.

Yet the “palaeoclimatic” record we generated for Madjedbebe indicates that, although glacial stages did lead to less rainfall, the Kakadu region remained relatively well-watered during these periods.

Our records show that for as long as people have been around, rainfall at Madjedbebe is unlikely to have dropped below current levels. Thus, this area would have helped early Australians survive during long dry spells and may have also attracted others from surrounding areas.

A site at the Madjedbebe is rock shelter in the Northern Territory.
This is our research site, the Madjedbebe rock shelter in the Alligator Rivers region of the Northern Territory.
Dominic O’Brien/Gundjeihmi Aboriginal Corporation, Author provided

Changing with the seasons

Our findings are supported by other archaeological evidence from Madjedbebe. For instance, our research has revealed more stone tools were left at this site during the glacial periods. This implies more people gathered there at these times.

Also, because the Kakadu region was still drier during glacial periods as compared to inter-glacial periods, people had to travel further for food and other important resources.




Read more:
Buried tools and pigments tell a new history of humans in Australia for 65,000 years


This is supported by evidence of an increased number of tools being brought to the site from further away. This points to increased mobility and new social arrangements being made as people adjusted to life in a harsher environment.

The challenge moving forward

Notably, over the past 65,000 years the driest time in the Kakadu region was not during the Last Glacial Maximum. It is today.

Rather than being the result of less rainfall occurring, this is likely due to higher evaporation caused by warmer inter-glacial temperatures. Aboriginal communities currently living in the Kakadu region are experiencing unprecedented aridity.

These difficult conditions are exacerbated by the threat of invasive plants and animals and disruption to cultural practices of landscape management, such as vegetation burning.

While the people of Kakadu have spent thousands of years adapting to environmental change, the scale and intensity of today’s anthropogenic impacts on regional climates and local landscapes poses an altogether different challenge.The Conversation

S. Anna Florin, Research fellow, University of Wollongong; Andrew Fairbairn, Professor of Archaeology, The University of Queensland; Chris Clarkson, Professor in Archaeology, The University of Queensland; James Shulmeister, Professor, School of Earth and Environmental Sciences, University of Canterbury; Nicholas R Patton, Ph.D. Candidate, University of Canterbury, and Patrick Roberts, Research Group Leader, Max Planck Institute for the Science of Human History

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Engineers have built machines to scrub CO₂ from the air. But will it halt climate change?



Climeworks

Deanna D’Alessandro, University of Sydney

On Wednesday this week, the concentration of carbon dioxide in the atmosphere was measured at at 415 parts per million (ppm). The level is the highest in human history, and is growing each year.

Amid all the focus on emissions reduction, the Intergovernmental Panel on Climate Change (IPCC) says it will not be enough to avoid dangerous levels of global warming. The world must actively remove historical CO₂ already in the atmosphere – a process often described as “negative emissions”.

CO₂ removal can be done in two ways. The first is by enhancing carbon storage in natural ecosystems, such as planting more forests or storing more carbon in soil. The second is by using direct air capture (DAC) technology that strips CO₂ from the ambient air, then either stores it underground or turns it into products.

US research published last week suggested global warming could be slowed with an emergency deployment of a fleet of “CO₂ scrubbers” using DAC technology. However a wartime level of funding from government and business would be needed. So is direct air capture worth the time and money?

Smoke stack with CO2 written in smoke
Direct air capture of CO2 will be needed to address climate change.
Shutterstock

What’s DAC all about?

Direct air capture refers to any mechanical system capturing CO₂ from the atmosphere. Plants operating today use a liquid solvent or solid sorbent to separate CO₂ from other gases.

Swiss company Climeworks operates 15 direct air capture machines across Europe, comprising the world’s first commercial DAC system. The operation is powered by renewable geothermal energy or energy produced by burning waste.

The machines use a fan to draw air into a “collector”, inside which a selective filter captures CO₂. Once the filter is full, the collector is closed and the CO₂ is sequestered underground.




Read more:
Net-zero, carbon-neutral, carbon-negative … confused by all the carbon jargon? Then read this


Canadian company Carbon Engineering uses giant fans to pull air into a tower-like structure. The air passes over a potassium hydroxide solution which chemically binds to the CO₂ molecules, and removes them from the air. The CO₂ is then concentrated, purified and compressed.

Captured CO₂ can be injected into the ground to extract oil, in some cases helping to counteract the emissions produced by burning the oil.

The proponents of the Climeworks and Carbon Engineering technology say their projects are set for large-scale investment and deployment in coming years. Globally, the potential market value of DAC technology could reach US$100bn by 2030, on some estimates.

Artist impression of a DAC facility to be built in Houston, Texas.
Artist impression of a DAC facility to be built in the US state of Texas. If built, it would be the largest of its kind in the world.
Carbon Engineering

Big challenges ahead

Direct air capture faces many hurdles and challenges before it can make a real dent in climate change.

DAC technology is currently expensive, relative to many alternative ways of capturing CO₂, but is expected to become cheaper as the technology scales up. The economic feasibility will be helped by the recent emergence of new carbon markets where negative emissions can be traded.

DAC machines process an enormous volume of air, and as such are very energy-intensive. In fact, research has suggested direct air capture machines could use a quarter of global energy in 2100. However new DAC methods being developed could cut the technology’s energy use.




Read more:
The Morrison government wants to suck CO₂ out of the atmosphere. Here are 7 ways to do it


While the challenges to direct air capture are great, the technology uses less land and water than other negative emissions technologies such as planting forests or storing CO₂ in soils or oceans.

DAC technology is also increasingly gaining the backing of big business. Microsoft, for example, last year included the technology in its carbon negative plan.

Emissions rising from a coal plant.
Direct air capture is touted as a way to offset emissions from industry and elsewhere.
Shutterstock

Opportunities for Australia

Australia is uniquely positioned to be a world leader in direct air capture. It boasts large areas of land not suitable for growing crops. It has ample sunlight, meaning there is great potential to host DAC facilities powered by solar energy. Australia also has some of the world’s best sites in which to “sequester” or store carbon in underground reservoirs.

Direct air capture is a relatively new concept in Australia. Australian company Southern Green Gas, as well as the CSIRO, are developing solar-powered DAC technologies. The SGG project, with which I am involved, involves modular units potentially deployed in large numbers, including close to sites where captured CO₂ can be used in oil recovery or permanently stored.

If DAC technology can overcome its hurdles, the benefits will extend beyond tackling climate change. It would create a new manufacturing sector and potentially re-employ workers displaced by the decline of fossil fuels.

Red sand and tussocks of grass
Australia has ample sunlight and plenty of non-arable land where DAC facilities could be built.
Shutterstock

Looking ahead

The urgency of removing CO₂ from the atmosphere seems like an enormous challenge. But not acting will bring far greater challenges: more climate and weather extremes, irreversible damage to biodiversity and ecosystems, species extinction and threats to health, food, water and economic growth.

DAC technology undoubtedly faces stiff headwinds. But with the right policy incentives and market drivers, it may be one of a suite of measures that start reversing climate change.




Read more:
Earth may temporarily pass dangerous 1.5℃ warming limit by 2024, major new report says


The Conversation


Deanna D’Alessandro, Professor & ARC Future Fellow, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Worried about Earth’s future? Well, the outlook is worse than even scientists can grasp



Daniel Mariuz/AAP

Corey J. A. Bradshaw, Flinders University; Daniel T. Blumstein, University of California, Los Angeles, and Paul Ehrlich, Stanford University

Anyone with even a passing interest in the global environment knows all is not well. But just how bad is the situation? Our new paper shows the outlook for life on Earth is more dire than is generally understood.

The research published today reviews more than 150 studies to produce a stark summary of the state of the natural world. We outline the likely future trends in biodiversity decline, mass extinction, climate disruption and planetary toxification. We clarify the gravity of the human predicament and provide a timely snapshot of the crises that must be addressed now.

The problems, all tied to human consumption and population growth, will almost certainly worsen over coming decades. The damage will be felt for centuries and threatens the survival of all species, including our own.

Our paper was authored by 17 leading scientists, including those from Flinders University, Stanford University and the University of California, Los Angeles. Our message might not be popular, and indeed is frightening. But scientists must be candid and accurate if humanity is to understand the enormity of the challenges we face.

Girl in breathing mask attached ot plant in container
Humanity must come to terms with the future we and future generations face.
Shutterstock

Getting to grips with the problem

First, we reviewed the extent to which experts grasp the scale of the threats to the biosphere and its lifeforms, including humanity. Alarmingly, the research shows future environmental conditions will be far more dangerous than experts currently believe.

This is largely because academics tend to specialise in one discipline, which means they’re in many cases unfamiliar with the complex system in which planetary-scale problems — and their potential solutions — exist.

What’s more, positive change can be impeded by governments rejecting or ignoring scientific advice, and ignorance of human behaviour by both technical experts and policymakers.

More broadly, the human optimism bias – thinking bad things are more likely to befall others than yourself – means many people underestimate the environmental crisis.

Numbers don’t lie

Our research also reviewed the current state of the global environment. While the problems are too numerous to cover in full here, they include:

  • a halving of vegetation biomass since the agricultural revolution around 11,000 years ago. Overall, humans have altered almost two-thirds of Earth’s land surface

  • About 1,300 documented species extinctions over the past 500 years, with many more unrecorded. More broadly, population sizes of animal species have declined by more than two-thirds over the last 50 years, suggesting more extinctions are imminent




Read more:
What is a ‘mass extinction’ and are we in one now?


  • about one million plant and animal species globally threatened with extinction. The combined mass of wild mammals today is less than one-quarter the mass before humans started colonising the planet. Insects are also disappearing rapidly in many regions

  • 85% of the global wetland area lost in 300 years, and more than 65% of the oceans compromised to some extent by humans

  • a halving of live coral cover on reefs in less than 200 years and a decrease in seagrass extent by 10% per decade over the last century. About 40% of kelp forests have declined in abundance, and the number of large predatory fishes is fewer than 30% of that a century ago.

State of the Earth's environment
Major environmental-change categories expressed as a percentage relative to intact baseline. Red indicates percentage of category damaged, lost or otherwise affected; blue indicates percentage intact, remaining or unaffected.
Frontiers in Conservation Science

A bad situation only getting worse

The human population has reached 7.8 billion – double what it was in 1970 – and is set to reach about 10 billion by 2050. More people equals more food insecurity, soil degradation, plastic pollution and biodiversity loss.

High population densities make pandemics more likely. They also drive overcrowding, unemployment, housing shortages and deteriorating infrastructure, and can spark conflicts leading to insurrections, terrorism, and war.




Read more:
Climate explained: why we need to focus on increased consumption as much as population growth


Essentially, humans have created an ecological Ponzi scheme. Consumption, as a percentage of Earth’s capacity to regenerate itself, has grown from 73% in 1960 to more than 170% today.

High-consuming countries like Australia, Canada and the US use multiple units of fossil-fuel energy to produce one energy unit of food. Energy consumption will therefore increase in the near future, especially as the global middle class grows.

Then there’s climate change. Humanity has already exceeded global warming of 1°C this century, and will almost assuredly exceed 1.5 °C between 2030 and 2052. Even if all nations party to the Paris Agreement ratify their commitments, warming would still reach between 2.6°C and 3.1°C by 2100.

people walking on a crowded street
The human population is set to reach 10 billion by 2050.
Shutterstock

The danger of political impotence

Our paper found global policymaking falls far short of addressing these existential threats. Securing Earth’s future requires prudent, long-term decisions. However this is impeded by short-term interests, and an economic system that concentrates wealth among a few individuals.

Right-wing populist leaders with anti-environment agendas are on the rise, and in many countries, environmental protest groups have been labelled “terrorists”. Environmentalism has become weaponised as a political ideology, rather than properly viewed as a universal mode of self-preservation.

Financed disinformation campaigns against climate action and forest protection, for example, protect short-term profits and claim meaningful environmental action is too costly – while ignoring the broader cost of not acting. By and large, it appears unlikely business investments will shift at sufficient scale to avoid environmental catastrophe.

Changing course

Fundamental change is required to avoid this ghastly future. Specifically, we and many others suggest:

  • abolishing the goal of perpetual economic growth

  • revealing the true cost of products and activities by forcing those who damage the environment to pay for its restoration, such as through carbon pricing

  • rapidly eliminating fossil fuels

  • regulating markets by curtailing monopolisation and limiting undue corporate influence on policy

  • reigning in corporate lobbying of political representatives

  • educating and empowering women across the globe, including giving them control over family planning.

A coal plant
The true cost of environmental damage should be borne by those responsible.
Shutterstock

Don’t look away

Many organisations and individuals are devoted to achieving these aims. However their messages have not sufficiently penetrated the policy, economic, political and academic realms to make much difference.

Failing to acknowledge the magnitude and gravity of problems facing humanity is not just naïve, it’s dangerous. And science has a big role to play here.

Scientists must not sugarcoat the overwhelming challenges ahead. Instead, they should tell it like it is. Anything else is at best misleading, and at worst potentially lethal for the human enterprise.




Read more:
Mass extinctions and climate change: why the speed of rising greenhouse gases matters


The Conversation


Corey J. A. Bradshaw, Matthew Flinders Professor of Global Ecology and Models Theme Leader for the ARC Centre of Excellence for Australian Biodiversity and Heritage, Flinders University; Daniel T. Blumstein, Professor in the Department of Ecology and Evolutionary Biology and the Institute of the Environment and Sustainability, University of California, Los Angeles, and Paul Ehrlich, President, Center for Conservation Biology, Bing Professor of Population Studies, Stanford University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Cities could get more than 4°C hotter by 2100. To keep cool in Australia, we urgently need a national planning policy



Shutterstock

Mark Maund, University of Newcastle; Kim Maund, University of Newcastle; Marcus Jefferies, University of Newcastle, and SueAnne Ware, University of Newcastle

In cities around the world, temperatures could rise by more than 4℃ by 2100 under a high-emissions climate change scenario, suggests research published this week in Nature Climate Change.

It comes as the Bureau of Meteorology’s annual climate statement, released today, shows 2020 was Australia’s fourth-warmest year on record, despite being an “La Niña” year, which usually leads to cooler temperatures.

Cities occupy just 3% of Earth’s surface. As this portion of land is so small, they’ve typically been left out of most climate models, which generally make projections on global scales.

Yet more than half the world’s population live in urban environments (set to jump to 70% by 2050). This is why the researchers call for “multi-model projections” of local climates for cities.

In the study, the researchers say their predictions on climate will give “urban planners and decision-makers in any city […] access to city-specific projections for any planning horizon they need”.

It’s important these planning horizons include the cooling and shading provided by green infrastructure — the network of green spaces such as street trees and green walls — in urban areas.




Read more:
Here’s how green infrastructure can easily be added to the urban planning toolkit


For Australia, this means getting a national green infrastructure policy that provides for green spaces within our cities, open spaces and buildings to help with increasing density and rising global temperatures.

What the research found

Heat events, such as heatwaves, pose a significant health risk and can hit people harder in cities.

Cities are hotter than in surrounding regional areas due to “the urban heat island” effect, a result of heat created by all the densely packed people, vehicles and industries, and the heat retained among buildings and other infrastructure.

Sydney highway
Cars, asphalt on roads, buildings and people, all densely packed together, are why cities are hotter than regional areas.
Shutterstock

Despite having the highest population density, the researchers point out that urban areas aren’t often represented in the Coupled Model Intercomparison Project. This project is important because it informs the global authority on climate change (the International Panel on Climate Change).

So the research authors built a statistical model emulating a complex climate model with urban regions. And they estimate that, by the end of the century, average warming across global cities will increase by 1.9℃ under an intermediate emissions scenario, and 4.4℃ with high emissions.

Urban warming would most affect mid-to-northern parts of the United States, southern Canada, Europe, the Middle East, northern Central Asia and northwestern China.




Read more:
Smart urban design could save lives in future heatwaves


They also predict that the heat index would increase faster than air temperature alone over almost all cities. “Heat index” refers to how hot the human body actually feels, a combination of relative humidity and air temperature. This would mean urban residents would experience higher heat stress.

What does this mean for Australia?

While the research found most urban warming would occur in the northern hemisphere, Australian cities are also projected to continue to warm. But we need only look to the recent record-breaking years to realise climate change will result in more extremely hot days here.

2019 was Australia’s hottest (and driest) year on record. And today’s annual climate statement from the Bureau of Meteorology shows the highest temperature ever recorded in the Sydney Basin, at a whopping 48.9℃, occurred in 2020, on January 4. It also found the average national temperature for 2020 was 1.15℃ higher than normal.

These are nationwide findings, but how Australia manages climate in urban areas is particularly important as around 80% of population growth occurs in capital cities.

In fact, 2020 research found we’re increasingly facing more frequent and prolonged heatwaves that intensify urban heat islands in places such as Sydney, by raising inland temperatures by as much as 10℃ more than in coastal zones.

Keeping cities cool

The best way to ensure our cities are kept cool is through greening urban spaces. Green spaces can be developed by planting trees in streets, yards and parks for shade, recreation and relief from the heat. This will create cooler urban “microclimates” for social interaction and natural retreats from city life.




Read more:
The world endured 2 extra heatwave days per decade since 1950 – but the worst is yet to come


Greater Sydney, for example, has a welcome new policy to ensure five million more trees are planted by 2030. This is an important long-term goal as 2016 research from Canada found tree cover in daytime reduced air temperature by up to 4℃ in Montreal city.

The design of buildings and their immediate surroundings are also important to help manage increasing heat in our cities.

Our open spaces are places of exercise, retreat, relaxation and, in a new COVID world, socially distant interactions. The pandemic has allowed us to rediscover the importance of our community and local connections in these spaces.

Multi-storey buildings also provide opportunity for vertical greening. The Victorian government, for example, is seeking to increase the amount of green infrastructure in our urban areas to help us cope with predicted warmer conditions.

Melbourne has many trees and green spaces that help negate the effects of the urban heat island.
Shutterstock

Australia needs a national planning policy

Urban planning and greening urban spaces is largely a local government responsibility, usually overseen by state and territory governments.

And there is national recognition of the importance of green cities through the federal government’s Smart Cities Plan. It states:

Green, sustainable cities […] improve the quality of air and water, reduce the heat island effect, protect biological diversity and threatened species, and enhance general amenity.

But what’s needed, urgently, is a national planning framework of green city principles so no regions get left behind. Climate change is a national issue, and all urban residents from all socioeconomic backgrounds should benefit from green cities.




Read more:
Anatomy of a heatwave: how Antarctica recorded a 20.75°C day last month


This national planning policy would describe how our cities across the nation should develop appropriately spaced trees and other vegetation, to better manage and prepare for increasing density and greater activity as climate change brings hotter weather.

And importantly, more research is needed to better inform climate models. We need more information into the ways our climates will change within different land areas — whether rural, suburban or in cities — so we can develop better national plans for how we will live and work in the future.




Read more:
In a heatwave, the leafy suburbs are even more advantaged


The Conversation


Mark Maund, Research Affiliate, School of Architecture and Built Environment, University of Newcastle; Kim Maund, Discipline Head – Construction Management, School of Architecture and Built Environment, University of Newcastle; Marcus Jefferies, Senior Lecturer School of Architecture and Built Environment, University of Newcastle, and SueAnne Ware, Professor and Head of School of Architecture and Built Environment, University of Newcastle

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Pikas are adapting to climate change remarkably well, contrary to many predictions



Stocking the haypile.
Arterra/Universal Images Group via Getty Images

Andrew Smith, Arizona State University

Climate change is harming many special places and iconic species around our planet, from Glacier National Park’s disappearing glaciers to California redwoods scorched by wildfires. But for the animal I study, the American pika (Ochotona princeps), there’s actually some good news: It’s not as threatened by climate change as many studies have warned.

I have studied pikas, small cousins of rabbits, for over 50 years and never tire of watching them. These tailless, egg-shaped balls of fluff live primarily in cool mountainous environments in piles of broken rock, called talus.

During summer, observers can see pikas industriously gathering caches of grass and leaves into haypiles that will serve as their food supply through the winter. Their light brown coats blend well with their surroundings, so they are easiest to spot when they perch on prominent rocks and call to alert other pikas of their presence.

Pikas’ calls range from short squeaks to a longer ‘song’

When fellow hikers see me observing pikas in California’s Sierra Nevada, they often tell me they have read that these animals are going extinct. I have collected a stack of press releases that say exactly that. But based on my recent research and a comprehensive review of over 100 peer-reviewed studies, I believe that this interpretation is misleading.

Constrained by climate

As I showed in my early research, pikas’ biology suggests that they are likely to be affected by a warming climate. Most important, their normal body temperature is high, and this puts them at risk of overheating when active in warm environments. When temperatures are warm, pikas retreat into the much cooler depths of their talus habitat.

Temperature also plays a role in pikas’ ability to move from place to place. Warm weather inhibits their movements, while cooler temperatures allow them to more freely colonize new habitats.

A little ancient history is instructive here. Pikas originally came to North America from Asia and spread across the continent some five million years ago, during colder times. Their remains have been found in caves in the Appalachian Mountains and in the Mojave Desert – sites where pikas no longer live.

Map of current pika range
American pikas live mainly in alpine and subalpine mountain areas extending south from central British Columbia and Alberta into the Rocky Mountains of New Mexico and the Sierra Nevada of California.
Andrew Smith, CC BY-ND

As the world’s climate warmed, pika populations retreated to the high mountains of the western U.S. and Canada. Today they occupy most of the available talus habitat in these areas – evidence that challenges the pikas-on-the-brink narrative.

For example, in recent surveys, pikas were found at 98% of 109 suitable sites in Colorado, and at 98% of 329 sites in the central Sierra Nevada. One study of historic pika sites across California’s Lassen, Yosemite, Kings Canyon and Sequoia National Parks found no evidence that pikas were moving to new sites or higher altitudes due to climate change.

Pikas in warm environments

In contrast, most sites where researchers believe that pikas have disappeared are small, isolated and often compromised by human activities, such as grazing by livestock. These sites generally are lower and warmer than sites in pikas’ core range.

Many of these areas are in the Great Basin – a large desert region spanning most of Nevada and parts of Utah, Idaho, Wyoming, Oregon and California. A series of studies on a small number of marginal Great Basin sites formerly occupied by pikas has disproportionately contributed to the narrative that pikas are likely to become endangered.

Great Basin map
Pikas have disappeared from some parts of the Great Basin, but climate change may not have been the cause.
Kmusser/Wikipedia, CC BY-SA

To investigate the big picture across this region, I worked with state and federal officials on a 2017 study that identified 3,250 site records of pika habitat. Pikas were present at 2,378 sites, not found at 89 sites where they had been seen as recently as 2005, and absent from 774 sites that contained only old signs of pika occupancy.

The extirpated and old sites had the same temperature and precipitation ranges as sites where pikas still were present. This suggests that non-climatic factors may have caused pikas’ disappearance from the vacant sites.

Pikas are still present in other remarkably hot places, such as the ghost town of Bodie, California, the nearby Mono Craters and Idaho’s Craters of the Moon National Monument. At these sites, pikas retreat into the cool nooks of their talus habitat during the warmest part of the day and often forage at night.

In my research, I also found that pikas were much less active and uttered far fewer calls at these low-altitude sites compared with high-elevation pika populations. At low-elevation sites, pikas consumed a diverse diet of Great Basin plants, such as big sagebrush and bitterbrush, that was markedly different from the plants they ate at high-elevation sites. Some even failed to construct their characteristic large haypiles.

Another atypical pika population lives near sea level in Oregon’s Columbia River Gorge. Here, too, they have adapted well to a very different habitat, surviving year-round on a diet that consists mainly of moss. They defend the smallest territories of any pika, and when it gets hot, they simply move off the talus and hang out in the shade of the nearby forest.

Pikas can make dozens of trips daily to build up their haypiles for winter.

A future for pikas

Based on my review of dozens of studies, pika populations appear to be secure in their core range – the mountains of western North America that have large and fairly well-connected talus habitat. In these areas they can move from one habitat patch to another without having to pass through areas that are dangerously warm for them.

The fact that pikas have also adapted to a number of marginal, hot environments suggests to me that they are more resilient to climate change than many past studies have concluded. Most species exhibit losses near the edges of their geographical ranges, simply because individual animals in those zones are living in conditions that are less than ideal for them. This does not mean that they are going extinct.

Climate change is the most critical issue facing the world today, so it is particularly important that scientists communicate accurately about it to the public. In my view, the fact that pikas are coping and altering their behaviors in response to changing conditions is encouraging news for future naturalists setting out to observe one of nature’s most charismatic mammals.The Conversation

Andrew Smith, Professor Emeritus of Life Sciences, Arizona State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The Marshall Islands could be wiped out by climate change – and their colonial history limits their ability to save themselves



The Marshall Islands and other small island nations are urgently threatened by rising seas.
Stefan Lins/Flickr, CC BY

Autumn Bordner, University of California, Berkeley and Caroline E. Ferguson, Stanford University

Along U.S. coastlines, from California to Florida, residents are getting increasingly accustomed to “king tides.” These extra-high tides cause flooding and wreak havoc on affected communities. As climate change raises sea levels, they are becoming more extreme.

King tides are nothing new for the Marshall Islands, a nation made up of 29 low-lying coral atolls that stretch across more than a million square miles of Pacific Ocean northeast of Australia. By 2035, the U.S. Geological Survey projects that some of the Marshall Islands will be submerged. Others will no longer have drinking water because their aquifers will be contaminated with saltwater. As a result, Marshallese would be forced to migrate away from their homelands.

This scenario is not inevitable. As part of our research on climate justice, we visited the Marshall Islands and interviewed leaders and community organizers in 2018 and 2019. We learned that large-scale adaptation measures that could save both these and other islands are still possible, and that Marshallese leaders are committed to adapting in place. But their nation’s colonial history has made it hard for them to act by leaving them dependent on foreign aid. And, to date, outside funders have been unwilling or unable to invest in projects that could save the nation.

Most of the world’s other island nations share similar colonial histories and face comparable climate challenges. Without swift and dramatic adaptation, entire island nations could become uninhabitable. For the Marshall Islands, this is expected to occur by midcentury.

The Marshall Islands span over 1 million square miles of ocean in the North Pacific.
Autumn Bordner

A radioactive legacy

The Marshall Islands were settled at least 2,000 years ago and fell under colonial rule during the 19th century. The U.S. captured the islands during World War II and became colonial administrator through the United Nations, accepting “sacred trust” obligations to protect the health and welfare of the Marshallese people and promote their political and economic self-determination.

Instead, from 1946 to 1958, the United States tested 67 nuclear weapons on inhabited Bikini and Enewetak Atolls, forcing these and other exposed communities to evacuate their homelands. Thousands of Marshallese remain in exile to this day, largely on tiny islands that are extremely climate-vulnerable or in the United States. Others have returned to their atolls, where radioactive fallout still contaminates the land. All of those exposed to radiation continue to face long-term health risks.

Marshall Islanders are forcibly evacuated from Bikini Atoll in 1948
Residents board a U.S. Navy ship, forcibly evacuated in March 1948 from Bikini Atoll for U.S. nuclear weapons testing.
U.S. Navy

The Marshall Islands gained sovereignty in 1986. But the U.S. retains full authority and responsibility for “security and defense matters in or relating to the Marshall Islands,” including the right to use Marshallese lands and waters for military activities.

Moreover, while the islands were a U.S. trust territory, the United States did not foster a self-sufficient economy. Instead, it injected large amounts of aid under the assumption that the islands were, in the words of Pacific scholar Epeli Hau’ofa,“too small, too poor and too isolated to develop any meaningful degree of autonomy.” The bulk of this aid went toward providing social services rather than promoting economic development, resulting in an economy based almost entirely on financial transfers from the U.S.

It’s not rocket science

What options does the Marshall Islands have for protecting its citizens from climate change? When we met with former National Climate Advisor Ben Graham in 2019, he told us that it will take “radical adaptation” to remain in place.

To control flooding driven by rising seas, the nation would need to reclaim and elevate land and consolidate its population in urban centers. Doing so is “not rocket science,” Graham told us. “China is building islands by the acre every day, Denmark is planning to construct nine artificial islands. … It’s not new, but it is expensive.”

According to Graham, implementing the forthcoming National Adaptation Plan will cost on the order of US$1 billion. That’s money the country doesn’t have.

But one atoll is likely to be saved: Kwajalein, which is occupied by the U.S. military. Already, the U.S. has made substantial investments to understand how sea level rise is affecting its military assets on Kwajalein.

Radical adaptation or forced migration?

Like most island states, the Marshall Islands relies heavily on external funding, often from former colonial administrators. Outside aid, primarily from organizations like the World Bank and donor countries like the U.S. and Australia, accounts for more than 25% of its gross domestic product, which in 2018 was $221.3 million.

These funders exert outsized control over the development agendas of the nations they support, including the power to decide which climate change adaptations are appropriate. In particular, funders tend to impose strict social and environmental safeguards, which limit the range of adaptation options the Marshall Islands and other aid-dependent sovereigns can pursue.

To date funders have only supported small-scale short-term projects, such as flood warning systems and improvements to tidal forecasting. And many have come to view migration as a suitable alternative to the type of large-scale adaptation that would allow nations to survive and people to live and thrive in their homelands. As Ben Graham put it to us, “there are those who say … your population is too small to spend half a billion dollars on it. Just relocate. It’s not worth keeping your culture and your sovereign status.”

But international law indicates that funders should not have the power to decide whether sovereign nations can survive climate change. The international norm of self-determination requires that decision to lie with the affected nation and its people. Yet unless the status quo is changed, the Marshallese face a forced migration caused by outside powers, just as they did 74 years ago as a result of U.S. nuclear weapons testing.

Island climate justice leaders

The Marshallese face overwhelming challenges, but they are not passive victims. The Marshall Islands was the first nation to increase its greenhouse gas reduction pledge under the Paris Agreement. Its representatives have served as tireless advocates for climate action and human rights on the international stage. And the Marshall Islands spearheaded the successful campaign to include a “well-below 2 degrees” warming target in the Climate Accords.

But they can’t fight alone. The nation’s president, David Kabua, recently called upon wealthy nations to live up to their Paris Agreement commitments to reduce emissions and mobilize the funding that vulnerable nations need to survive.

Two Indigenous poets, Kathy Jetñil-Kijiner from the Marshall Islands and Aka Niviâna from Greenland, meet at the source of rising seas to share a moment of solidarity.

[Get our best science, health and technology stories. Sign up for The Conversation’s science newsletter.]

For years, the U.S. and other developed nations have failed to reduce their greenhouse gas emissions quickly enough to meet targets in the Paris climate agreement that are intended to avoid warming on a catastrophic scale. They have also failed to meet their pledges to help vulnerable states adapt to climate change. The U.S., meanwhile, has refused to provide over $2 billion that an independent nuclear claims tribunal awarded to the Marshall Islands as compensation for damage caused by nuclear testing.

The incoming Biden administration has a chance to change course. We believe that the U.S. should provide direct support for Marshallese climate adaptation efforts. This would help to redress the long history of use and abuse, broken promises, and unfulfilled obligations that has left the Marshall Islands so exceptionally climate-vulnerable today.The Conversation

Autumn Bordner, Research Fellow, University of California, Berkeley and Caroline E. Ferguson, PhD candidate in Environment and Resources, Stanford University

This article is republished from The Conversation under a Creative Commons license. Read the original article.