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


Thomas La Mela/Shutterstock

Glenn Banks, Massey University


CC BY-ND

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz

Almost every threat to modern humanity can be traced simply to our out-of-control population growth (think about arable land going to housing; continued growth in demand for petroleum fuels). Is anything being done to contain population growth on a national and international scale?

The question of population is more complex that it may seem – in the context of climate change as well as other issues such as biodiversity loss and international development.

As a starting point, let’s look at the statement “out-of-control population growth”. In fact, population growth is more “in control” than it has been for the past 50 years.




Read more:
Climate explained: how growth in population and consumption drives planetary change


Population isn’t growing everywhere

The global rate of population growth has been declining from just over 2% per year in 1970 to less than 1.1% in 2020 (and this estimate was made before COVID-19 erupted globally).

To put this in perspective, if the 2% growth rate had continued, the world’s population would have doubled in 35 years. At a 1.1% growth rate, it would now be set to double in 63 years – but the growth rate is still declining, so the doubling time will be lengthened again.

Population growth also varies significantly between countries. Among the 20 most populous countries in the world, three countries have growth rates of more than 2.5% – Ethiopia, Nigeria and the Democratic Republic of Congo – while Japan’s population is in decline (with a negative growth rate, -0.3%) and China, Russia, Germany and Thailand all have very low growth rates.

These growth rates vary in part because the population structures are very different across countries. Japan has an aged population, with 28% over 65 years and just 12% under 15 years. Nigeria has only 3% of people in the over-65 bracket and 44% under 15.

For comparison, 20% of New Zealanders are younger than 15 and 16% are older than 65. For Australia, the respective figures are 18% and 17%.

Migration also makes a significant contribution in some countries, propping up the working-age population and shaping the demographic structure. History and levels of economic development play an important role too: higher-income countries almost consistently have smaller families and lower growth rates.

Rise in consumption

It’s certainly valid to link population growth (even a more limited “in control” population growth) with climate change and loss of land. Everything else being equal, more people means more space taken up, more resources consumed and more carbon emitted.

But while population growth has slowed since the 1970s, resource consumption hasn’t. For example, there is no equivalent decline in fossil fuel use since the 1970s.

Fuel consumption varies throughout the world.
Flickr/Minnesota Pollution Control Agency, CC BY-NC

This is an area where not everyone is equal. If all people were to use the same amount of resources (fossil fuels, timber, minerals, arable land etc), then of course total resource use and carbon would rise. But resource use varies dramatically globally.

If we look at oil consumption per person in 2019, the average American used almost twice as much as someone in Japan, the second oil-thirstiest populous nation, and almost 350 times as much as a person living in the Democratic Republic of Congo.

It is an easy out for us in the industrialised world to say “out-of-control population growth” is killing the planet, when instead it is equally valid – but more confronting – to say our out-of-control consumption is killing the planet.




Read more:
Can your actions really save the planet? ‘Planetary accounting’ has the answer


Population growth slows when women are educated

To come to the final part of the question: is anything being done to contain population growth, on a national or international scale?

Even if we set aside the argument above that population is not the only issue, or even the most significant one, in terms of threats to humanity, what factors might influence population growth in parts of the world where it is high?

Things are being done, but they may not be what most people expect. It has long been shown that as incomes rise and health care improves, more children survive and people tend to have smaller families.

This effect is not instantaneous. There is a lag where population growth rates might rise first before they begin to drop. This demographic transition is a relatively consistent pattern globally.

But, at the country level, the single most significant influence on reducing fertility rates, family size and overall population growth is access to education for girls and women.

Fertility rates drop when girls get access to education.
Oksana Kuzmina/Shutterstock

One study in 2016, drawing on World Bank population data across a wide range of countries, found:

… the main driver of overall fertility reduction is clearly the change in proportions of women at each education level.

In relation to climate change action, this study specifically notes:

It is education, or more specifically girls’ education, that is far more likely to result in lower carbon emissions than a shift to renewables, improved agricultural practices, urban public transport, or any other strategy now being contemplated.

Recent research looked at how the global population might change if we implemented the aspirations of the 17 UN Sustainable Development Goals. It found the change would be significant and could even mean the global population stabilises by mid-century.The Conversation

Glenn Banks, Professor of Geography and Head of School, School of People, Environment and Planning, Massey University

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

Climate explained: why higher carbon dioxide levels aren’t good news, even if some plants grow faster



Shutterstock

Sebastian Leuzinger, Auckland University of Technology

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz

If carbon dioxide levels were to double, how much increase in plant growth would this cause? How much of the world’s deserts would disappear due to plants’ increased drought tolerance in a high carbon dioxide environment?

Compared to pre-industrial levels, the concentration of carbon dioxide (CO₂) in the atmosphere will have doubled in about 20 to 30 years, depending on how much CO₂ we emit over the coming years. More CO₂ generally leads to higher rates of photosynthesis and less water consumption in plants.

At first sight, it seems more CO₂ can only be beneficial to plants, but things are a lot more complex than that.




Read more:
Climate explained: why plants don’t simply grow faster with more carbon dioxide in air


Let’s look at the first part of the question.

Some plants do grow faster under elevated levels of atmospheric CO₂, but this happens mostly in crops and young trees, and generally not in mature forests.

Even if plants grew twice as fast under doubled CO₂ levels, it would not mean they strip twice as much CO₂ from the atmosphere. Plants take carbon from the atmosphere as they grow, but that carbon is going straight back via natural decomposition when plants die or when they are harvested and consumed.

At best, you might be mowing your lawn twice as often or harvesting your plantation forests earlier.

The most important aspect is how long the carbon stays locked away from the atmosphere – and this is where we have to make a clear distinction between increased carbon flux (faster growth) or an increasing carbon pool (actual carbon sequestration). Your bank account is a useful analogy to illustrate this difference: fluxes are transfers, pools are balances.




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Climate explained: why your backyard lawn doesn’t help reduce carbon dioxide in the atmosphere


The global carbon budget

Of the almost 10 billion tonnes (gigatonnes, or Gt) of carbon we emit every year through the burning of fossil fuels, only about half accumulates in the atmosphere. Around a quarter ends up in the ocean (about 2.4 Gt), and the remainder (about 3 Gt) is thought to be taken up by terrestrial plants.

While the ocean and the atmospheric sinks are relatively easy to quantify, the terrestrial sink isn’t. In fact, the 3 Gt can be thought of more as an unaccounted residual. Ultimately, the emitted carbon needs to go somewhere, and if it isn’t the ocean or the atmosphere, it must be the land.

So yes, the terrestrial system takes up a substantial proportion of the carbon we emit, but the attribution of this sink to elevated levels of CO₂ is difficult. This is because many other factors may contribute to the land carbon sink: rising temperature, increased use of fertilisers and atmospheric nitrogen deposition, changed land management (including land abandonment), and changes in species composition.

Current estimates assign about a quarter of this land sink to elevated levels of CO₂, but estimates are very uncertain.

In summary, rising CO₂ leads to faster plant growth – sometimes. And this increased growth only partly contributes to sequestering carbon from the atmosphere. The important questions are how long this carbon is locked away from the atmosphere, and how much longer the currently observed land sink will continue.




Read more:
Climate explained: how different crops or trees help strip carbon dioxide from the air


The second part of the question refers to a side-effect of rising levels of CO₂ in the air: the fact that it enables plants to save water.

Plants regulate the exchange of carbon dioxide and water vapour by opening or closing small pores, called stomata, on the surface of their leaves. Under higher concentrations of CO₂, they can reduce the opening of these pores, and that in turn means they lose less water.

This alleviates drought stress in already dry areas. But again, the issue is more complex because CO₂ is not the only parameter that changes. Dry areas also get warmer, which means that more water evaporates and this often compensates for the water-saving effect.

Overall, rising CO₂ has contributed to some degree to the greening of Earth, but it is likely that this trend will not continue under the much more complex combination of global change drivers, particularly in arid regions.The Conversation

Sebastian Leuzinger, Professor, Auckland University of Technology

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

As Earth’s population heads to 10 billion, does anything Australians do on climate change matter?



The United Nations predicts the world will be home to nearly 10 billion people by 2050 – making global greenhouse emission cuts ever more urgent.
NASA/Joshua Stevens

Mark Beeson, University of Western Australia

As unprecedented bushfires continue to ravage the country, Prime Minister Scott Morrison and his government have been rightly criticised for their reluctance to talk about the underlying drivers of this crisis. Yet it’s not hard to see why they might be dumbstruck.

The human race has never had to grapple with a problem as large, complex or urgent as climate change. It’s not that there aren’t solutions available. There are already some hopeful signs of an energy transition in Australia. As Professor Ross Garnaut has explained, it would be in Australia’s economic interests to become a low-carbon energy superpower.

To successfully tackle climate change will require some painful transitions domestically, and unprecedented levels of international coordination and cooperation. But that isn’t happening. Global action to cut emissions is falling far short of what’s needed – and meanwhile, though it’s controversial to mention, the world’s population quietly climbs ever higher.

Our growing population challenge

The United Nations’ World Population Prospects 2019 report forecast that by 2027, India will overtake China as the world’s most populous country.

By 2050, the UN predicts that the world’s population will be nearly 10 billion, up from 7.7 billion now. Nine countries are expected to be home to more than half of that growth: India, Nigeria, Pakistan, the Congo, Ethiopia, Tanzania, Indonesia, Egypt and the United States. The population of sub-Saharan Africa is expected to double by 2050 (a 99% increase), while Australia and New Zealand are expected to grow more slowly (28% increase).

The world’s population growth rate in recent years.
World Population Prospects 2019, United Nations, CC BY

Given how difficult climate politics have been here in Australia, why would we expect it to be any more politically feasible in say, India, which claims the right to develop as we did? However self-serving Australian coal supporters’ arguments about lifting Indians out of poverty are, the underlying questions of national autonomy and the ‘right’ to develop are not easily refuted.

Even talking about demography is asking for trouble – especially if it becomes caught up with questions of race, identity and the most fundamental of human rights, the right to reproduce.

While reducing population growth is plainly important in the long-term, it isn’t a quick fix for all our environmental problems. In the meantime, research has shown that supporting education for girls in poor countries is one of the single most important things we can do now to address this issue.

How Australia can show leadership

I think we need to understand that global emissions don’t have an accent, they come from many countries and we need to look at a global solution… – Prime Minister Scott Morrison on Insiders, ABC, 12 January 2020

This is the central defence of business as usual: there’s no point in Australia making huge sacrifices and ‘wrecking’ (or transforming, depending on your perspective) the economy if no one else is doing so. We contribute less than 2% to global greenhouse emissions, so – some claim – we can’t make any real difference.

As outlined in my 2019 book, Environmental Populism: The Politics of Survival in the Anthropocene, nations such as Australia can play a useful role by showing what an enlightened country, with the capacity and incentive to act, might do. If we don’t have the means and the compelling environmental reasons to make tough but meaningful policy choices, who does?

But even in the unlikely event that Australians collectively retrofitted the entire economy along sustainable lines, there would still be a lot of the world that wouldn’t, or couldn’t even if they wanted to. The development imperative really is non-negotiable in India, China and the more impoverished states of sub-Saharan Africa.

Will China lead the way?

From the privileged perspective of wealthy Australians, the ‘good’ news is that the ecological footprint of the average Ethiopian is seven times smaller than ours. India’s average is even less, despite all the recent development. However, people in India and Ethiopia may not think that’s a good thing.

One of the paradoxical impacts of globalisation is that everyone is increasingly conscious of their relative place in the international scheme of things. The legitimacy of governments – especially unelected authoritarian regimes like China’s – increasingly revolves around their capacity to deliver jobs and rising living standards. Where governments can’t deliver, the population vote with their feet.

As naturalist Sir David Attenborough warned last week, Australia’s current fires are another sign that “the moment of crisis has come”. He called on China for the global leadership we’ve been missing:

If the Chinese come and say: ‘Not because we are worried about the world but for our own reasons, we are going to take major steps to curb our carbon output […]’, everybody else would fall into line, one thinks. That would be the big change that one could hope would happen.

China has arguably already made the biggest contribution to our collective welfare with its highly contentious, now abandoned one-child policy. China’s population would have been around 400 million people larger without it, pushing us closer to the crisis Sir David fears.

To be clear, I’m not advocating compulsory population control, here or anywhere. But we do need to consider a future with billions more people, many of them aspiring to live as Australians do now.

Looking ahead, will Australians try to keep living as we do today? Or will we decide to set a new example of living well, without such a heavy ecological footprint? Resolving all these conundrums won’t be easy; perhaps not even possible. That’s another discomfiting reality that we may have to get used to.The Conversation

Mark Beeson, Professor of International Politics, University of Western Australia

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

Urban growth, heat islands, humidity, climate change: the costs multiply in tropical cities



During a heatwave in late 2018, Cairns temperatures topped 35°C nine days in a row and sensors at some points in the CBD recorded 45°C.

Taha Chaiechi, James Cook University and Silvia Tavares, James Cook University

Some 60% of the planet’s expected urban area by 2030 is yet to be built. This forecast highlights how rapidly the world’s people are becoming urban. Cities now occupy about 2% of the world’s land area, but are home to about 55% of the world’s people and generate more than 70% of global GDP, plus the associated greenhouse gas emissions.

So what does this mean for people who live in the tropical zones, where 40% of the world’s population lives? On current trends, this figure will rise to 50% by 2050. With tropical economies growing some 20% faster than the rest of the world, the result is a swift expansion of tropical cities.

Population and number of cities of the world, by size class, 1990, 2018 and 2030.
World Urbanization Prospects 2018, United Nations DESA Population Division, CC BY



Read more:
Healthy, happy and tropical – world’s fastest-growing cities demand our attention


The populations of these growing tropical cities already experience high temperatures made worse by high humidity. This means they are highly vulnerable to extreme heat events as a result of climate change.

For example, extremely hot weather overwhelmed Cairns last summer. By December 3 2018, the city had recorded temperatures above 35°C nine days in a row. Four consecutive days were above 40°C.

Cairns’ heatwave summer.
Authors, using BOM temperature data

For our research, temperature and humidity sensors were strategically placed in the Cairns CBD to represent people’s experience of weather at street level. These recorded temperatures consistently higher than the Bureau of Meteorology (BoM) recordings, reaching 45°C at some points.

Highest temperatures recorded by James Cook University weather data sensors during the November-December 2018 heatwave in Cairns.
Image: Bronson Philippa, Author provided

Local effects magnify heatwave impacts

Urban environments in general are hotter than non-urbanised surroundings that are covered by vegetation. The trapping of heat in cities, known as the urban heat island effect, has impacts on human health, animal life, social events, tourism, water availability and business performance.

The urban heat island effect intensifies the impacts of increasing heatwaves on cities as a result of climate change.

Projections of increased heatwave frequency for Cairns region using visualisation platform on Queensland Future Climate Dashboard.
Queensland Future Climate Dashboard/Queensland Government, CC BY

But it is important to remember that other local factors also influence these impacts. These include the scale, shape, materials, composition and growth of the built environment in a particular location and its surrounding areas.

The differences between the BoM data recorded at Cairns airport and the inner-city recordings show the impacts of urban expansion patterns, built form and choice of materials in tropical cities.

The linear layout of Cairns has, on one hand, enabled the formation of attractive places for commercial activities. As these activity centres evolve into focal points of urban life, they in turn influence all sorts of socioeconomic parameters.

On the other hand, the form the built environment takes changes the patterns of wind, sun and shade. These changes alter the urban microclimate by trapping heat and slowing or channelling air movements.

The layout and structures of Cairns CBD alter local microclimates by trapping heat and altering air flows.
State of Queensland 2019, CC BY



Read more:
City temperatures and city economics, a hidden relationship between sun and wind and profits


Shifting the focus to the tropics

To date, a large body of research has explored the undesired consequences of climate change and urban heat islands. However, the focus has been on capital and metropolitan cities with humid continental climates. Not many studies have looked at the economic and social impacts in the tropical context, where hot and humid conditions create extra heat stress.

Add the combined effects of climate change and urban heat islands and what are the socio-economic consequences of heatwaves in a tropical city like Cairns? We see that climate change adds another dimension to the relationship between cities, economic growth and development.

This presents a huge opportunity to start thinking about building cities that are not superficially greenwashed, but which instead tackle pressing issues such as climate variability and create sustainable business and social destinations.




Read more:
Requiem or renewal? This is how a tropical city like Darwin can regain its cool


In cold climates, heatwaves and urban heat islands are not necessarily undesired, but their negative impacts are more obvious and harmful in warmer climates. And these harmful impacts of heatwaves on our economy, environment and society are on the rise.

We have scientific evidence of the increasing length, frequency and intensity of heatwaves. The number of record hot days in Australia has doubled in the past five decades.

Projections of changes in heatwave frequency for northern Queensland in 2030 and 2070.
Queensland Future Climate Dashboard/Queensland Government, CC BY

What are the costs of heatwaves?

Increased exposure to heatwaves amplifies the adverse economic impacts on industries that are reliant on the health of their outdoor workers. This is in addition to the extreme heat-related fatalities and health-care costs of heatwave-related medical emergencies. As a PwC report to the Commonwealth on extreme heat events stated:

Heatwaves kill more Australians than any other natural disaster. They have received far less public attention than cyclones, floods or bushfires — they are private, silent deaths, which only hit the media when morgues reach capacity or infrastructure fails.

Heat also has direct impacts on economic production. A 2010 study found a 1°C increase resulted in a 2.4% reduction in non-agricultural production and a 0.1% reduction in agricultural production in 28 Caribbean-basin countries. Another study in 2012 found an 8% weekly loss of production when the temperature exceeded 32°C for six days in a row.

The 2017 Farm performance and climate report by the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES) states:

The recent changes in climate have had a significant negative effect on the productivity of Australian cropping farms, particularly in southwestern Australia and southeastern Australia.

Average climate effect on productivity of cropping farms in southwestern and southeastern Australia since 2000–01 (relative to average conditions from 1914–15 to 2014–15).
Farm performance and climate, ABARES, CC BY

It’s not just farming that is vulnerable. A Victorian government report report this year estimated an extreme heatwave event costs the state’s construction sector A$103 million. The impact of heatwaves on the city of Melbourne’s economy is estimated at A$52.9 million a year on average.

Impacts of heatwaves on Victoria’s main economic sectors.
State of Victoria Department of Environment, Land, Water and Planning, CC BY

According to this report, economic costs increase exponentially as the severity of heatwaves increases. This has obvious implications for cities in tropical regions.

As the next step in our research, we are examining the relationship between local urban features, urban heat islands, the resulting city temperatures and their direct and indirect (spillover) effects on local and regional economic activities.




Read more:
Making a global agenda work locally for healthy, sustainable living in tropical Australia


The Conversation


Taha Chaiechi, Senior Lecturer, James Cook University and Silvia Tavares, Lecturer in Urban Design, James Cook University

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

Climate explained: why plants don’t simply grow faster with more carbon dioxide in air



Fast-growing plantation trees store less carbon per surface area than old, undisturbed forests that may show little growth.
from http://www.shutterstock.com, CC BY-ND

Sebastian Leuzinger, Auckland University of Technology


CC BY-ND

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz

Carbon dioxide is a fertiliser for plants, so if its concentration increases in the atmosphere then plants will grow better. So what is the problem? – a question from Doug in Lower Hutt

Rising atmospheric carbon dioxide (CO₂) is warming our climate, but it also affects plants directly.

A tree planted in the 1850s will have seen its diet (in terms of atmospheric carbon dioxide) double from its early days to the middle of our century. More CO₂ generally leads to higher rates of photosynthesis and less water consumption in plants. So, at first sight, it seems that CO₂ can only be beneficial for our plants.

But things are a lot more complex than that. Higher levels of photosynthesis don’t necessarily lead to more biomass production, let alone to more carbon dioxide sequestration. At night, plants release CO₂ just like animals or humans, and if those respiration rates increase simultaneously, the turnover of carbon increases, but the carbon stock doesn’t. You can think of this like a bank account – if you earn more but also spend more, you’re not becoming any richer.

Even if plants grow more and faster, some studies show there is a risk for them to have shorter lifespans. This again can have negative effects on the carbon locked away in biomass and soils. In fact, fast-growing trees (e.g. plantation forests) store a lot less carbon per surface area than old, undisturbed forests that show very little growth. Another example shows that plants in the deep shade may profit from higher levels of CO₂, leading to more vigorous growth of vines, faster turnover, and, again, less carbon stored per surface area.




Read more:
Want to beat climate change? Protect our natural forests


Water savings

The effect of CO₂ on the amount of water plants use may be more important than the primary effect on photosynthesis. Plants tend to close their leaf pores slightly under elevated levels of CO₂, leading to water savings. In certain (dry) areas, this may indeed lead to more plant growth.

But again, things are much more complex and we don’t always see positive responses. Research we published in Nature Plants this year on grasslands around the globe showed that while dry sites can profit from more CO₂, there are complex interactions with rainfall. Depending on when the rain falls, some sites show zero or even negative effects in terms of biomass production.

Currently, a net amount of three gigatons of carbon are thought to be removed from the atmosphere by plants every year. This stands against over 11 gigatons of human-induced release of CO₂. It is also unclear what fraction of the three gigatons plants are taking up due to rising levels of CO₂.

In summary, rising CO₂ is certainly not bad for plants, and if we restored forested land at a global scale, we could help capture additional atmospheric carbon dioxide. But such simulations are optimistic and rely on conversion of much needed agricultural land to forests. Reductions in our emissions are unavoidable, and we have very strong evidence that plants alone will not be able to solve our CO₂ problem.




Read more:
Exaggerating how much CO₂ can be absorbed by tree planting risks deterring crucial climate action


The Conversation


Sebastian Leuzinger, Associate Professor, Auckland University of Technology

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

Our legacy of liveable cities won’t last without a visionary response to growth



File 20180327 188613 1komx6d.jpg?ixlib=rb 1.1
Historic investments in green open space along the Yarra created a legacy of liveability in Melbourne.
Ispas Vlad/Shutterstock

Chris Chesterfield, Monash University

Australia’s major cities are growing more rapidly than ever before, gaining three million residents in a decade. Concerns about the risks to their long-term liveability and health are growing too. Is the consistent placing of Australian cities at the top of most liveable city rankings a reason for complacency?

The fastest-growing city, Melbourne, is experiencing unprecedented growth and yet has topped The Economist Intelligence Unit global liveability ranking for seven years running. However, much like Australia’s remarkable record of 26 years of continuous economic growth, many of the policy and institutional reforms that delivered this liveability legacy occurred decades ago.




Read more:
Three charts on Australia’s population shift and the big city squeeze


Australia is now undergoing its third great wave of population growth, putting pressure on infrastructure, services and the environment. During the past two waves of growth, in the late-19th and mid-20th centuries, cities implemented visionary responses. It’s largely because of these past phases of planning and investment that our cities have until now been able to sustain their liveability and a reasonably healthy natural environment.

A third wave of planning and investment in open space and green infrastructure is now needed to underpin liveability as our cities grow. The past offers important lessons about what made Melbourne, in particular, so liveable.

Can we repeat the leadership of yesterday?

In the early 19th century, European settlers ignored and displaced the Indigenous knowledge and connections with country. What grew in their place were initially little more than shambolic frontier towns.

In the Port Phillip colony, the gold rush, the subsequent population and property booms and the lack of city services led to Melbourne gaining an international reputation as “Smellbourne”.

But then, over several decades, visionary plans set aside a great, green arc of parklands and tree-lined boulevards around the city grid.

Melbourne constructed one of the world’s earliest sewerage systems. The forested headwaters of the Yarra River were reserved for water supply. Melbourne is today one of a handful of major cities in the world drawing its natural water supplies from closed catchments.

And so, together with profound social and cultural changes, the shambolic frontier town transformed into “Marvellous Melbourne”. Sydney and Australia’s other capital cities followed similar trajectories.




Read more:
All the signs point to our big cities’ need for democratic, metro-scale governance


Then came the world wars and intervening Great Depression. These were times of austerity and sacrifice. Remarkably little investment in open space and green infrastructure occurred over these decades.

The 1956 Melbourne Olympics was perhaps the event that signalled the awakening from that somewhat bleak period. It was again time for optimism and vision, with the post-war population boom well under way.

Australia’s population was booming at the time of the 1956 Melbourne Olympics, with growth averaging 2.7% a year from 1945-1960 (the 2007-17 average is 1.7%).
Tidningarnas Telegrambyrå/Wikimedia

The 1954 Melbourne Metropolitan Planning Scheme reflected this growing optimism and highlighted the potential for a network of open spaces across the rapidly expanding city. But it took time to build momentum for its implementation.

By the 1970s sprawling development had virtually doubled the metropolitan area of Melbourne. Services such as the sewerage system had not kept up. The Yarra and other waterways and Port Phillip Bay were becoming grossly polluted. There was community pressure to tackle pollution caused by industry and unsewered suburbs.

In 1971, the Victorian Environment Protection Authority, the second EPA in the world, was created to regulate industry. State and federal governments made a huge investment in sewering the suburbs.

The city’s planners revived the earlier vision for Melbourne’s open space network, along with the idea of green wedges and development corridors. Greater prosperity and community expectation secured the investment needed to deliver it.

Historic decisions to protect the Yarra River have had lasting benefits for Melbourne.
Dorothy Chiron/Shutterstock

The 1971 metropolitan plan identified open-space corridors for waterways including the Yarra. Land began to be acquired to build this green network and the trail systems that connect it. Victoria became known as the “Garden State” in the 1970s.

This period stands out as the city’s second great wave of visionary planning and investment. It created the wonderful legacy of a world-class network of open space, much of it around waterways and Port Phillip Bay.

Where to today?

Sustaining or improving urban liveability is a massive challenge. It calls for a new vision and a commitment by governments to deliver it over many decades. Do we have policies and institutions capable of doing this?

Rather than “shaping” our cities, many state institutions are dominated by cost and efficiency goals that drive a “city servicing” mindset.

Melbourne, for instance, is in danger of exhausting the legacy of the last “city shaping” phase of visionary planning and investment. This all but ended in the 1980s.

By 1992, the Melbourne and Metropolitan Board of Works had been abolished. It once had responsibility for town planning, parks, waterways and floodplain management as well as water and sewerage services. It used the Metropolitan Improvement Fund (raised from city-wide property levies) to plan and deliver the city’s green infrastructure, including land acquisitions.

Where is the equivalent capability today? Our practitioners have the knowledge, skills and understanding to better plan for complex city needs, but this is not enough to shape a better future for coming generations. Without a vision and effective policies and institutions to deliver it, we risk ad hoc and wasteful decision-making and investment. The result will be poorer community well-being and less economic prosperity.




Read more:
City planning suffers growth pains of Australia’s population boom


The entrenched cost-efficiency or “city servicing” mindset is an all-too-narrow and short-term policy setting in an era of unprecedented urban population growth.

Expanding suburban fringes will lack amenity and a healthy environment, which may entrench disadvantage. Existing suburbs also need to improve quality, access and connectivity of public open space.

Green streetscapes, open space and tree cover are important for amenity. This includes countering urban heat in a warming climate. Co-ordinated investment in green infrastructure can also unlock new economic opportunities for our cities.

But, as the past has shown, little will happen without an effective city-shaping capability. Significant policy and institutional reforms, guided by a new vision, are essential to ensure a healthy environment, community well-being and the liveability and prosperity of our cities for decades to come.

The ConversationAlternatively, we may find ourselves tumbling down the ranks of world’s most liveable cities. Our best and brightest will be drawn to greener pastures while the world asks in astonishment, “How did they let that happen?”

Chris Chesterfield, Director Strategic Engagement, CRC for Water Sensitive Cities, Monash University

This article was originally published on The Conversation. Read the original article.

Fossil fuel emissions hit record high after unexpected growth: Global Carbon Budget 2017


Pep Canadell, CSIRO; Corinne Le Quéré, University of East Anglia; Glen Peters, Center for International Climate and Environment Research – Oslo; Robbie Andrew, Center for International Climate and Environment Research – Oslo; Rob Jackson, Stanford University, and Vanessa Haverd, CSIRO

Global greenhouse emissions from fossil fuels and industry are on track to grow by 2% in 2017, reaching a new record high of 37 billion tonnes of carbon dioxide, according to the 2017 Global Carbon Budget, released today.

The rise follows a remarkable three-year period during which global CO₂ emissions barely grew, despite strong global economic growth.

But this year’s figures suggest that the keenly anticipated global peak in emissions – after which greenhouse emissions would ultimately begin to decline – has yet to arrive.


Read more: Fossil fuel emissions have stalled: Global Carbon Budget 2016


The Global Carbon Budget, now in its 12th year, brings together scientists and climate data from around the world to develop the most complete picture available of global greenhouse gas emissions.

In a series of three papers, the Global Carbon Project’s 2017 report card assesses changes in Earth’s sources and sinks of CO₂, both natural and human-induced. All excess CO₂ remaining in the atmosphere leads to global warming.

We believe society is unlikely to return to the high emissions growth rates of recent decades, given continued improvements in energy efficiency and rapid growth in low-carbon energies. Nevertheless, our results are a reminder that there is no room for complacency if we are to meet the goals of the Paris Agreement, which calls for temperatures to be stabilised at “well below 2℃ above pre-industrial levels”. This requires net zero global emissions soon after 2050.

After a brief plateau, 2017’s emissions are forecast to hit a new high.
Global Carbon Project, Author provided

National trends

The most significant factor in the resumption of global emissions growth is the projected 3.5% increase in China’s emissions. This is the result of higher energy demand, particularly from the industrial sector, along with a decline in hydro power use because of below-average rainfall. China’s coal consumption grew by 3%, while oil (5%) and gas (12%) continued rising. The 2017 growth may result from economic stimulus from the Chinese government, and may not continue in the years ahead.

The United States and Europe, the second and third top emitters, continued their decade-long decline in emissions, but at a reduced pace in 2017.

For the US, the slowdown comes from a decline in the use of natural gas because of higher prices, with the loss of its market share taken by renewables and to a lesser extent coal. Importantly, 2017 will be the first time in five years that US coal consumption is projected to rise slightly (by about 0.5%).

The EU has now had three years (including 2017) with little or no decline in emissions, as declines in coal consumption have been offset by growth in oil and gas.

Unexpectedly, India’s CO₂ emissions will grow only about 2% this year, compared with an average 6% per year over the past decade. This reduced growth rate is likely to be short-lived, as it was linked to reduced exports, lower consumer demand, and a temporary fall in currency circulation attributable to demonetisation late in 2016.

Trends for the biggest emitters, and everyone else.
Global Carbon Project, Author provided

Yet despite this year’s uptick, economies are now decarbonising with a momentum that was difficult to imagine just a decade ago. There are now 22 countries, for example, for which CO₂ emissions have declined over the past decade while their economies have continued to grow.

Concerns have been raised in the past about countries simply moving their emissions outside their borders. But since 2007, the total emissions outsourced by countries with emissions targets under the Kyoto Protocol (that is, developed countries, including the US) has declined.

This suggests that the downward trends in emissions of the past decade are driven by real changes to economies and energy systems, and not just to offshoring emissions.

Other countries, such as Russia, Mexico, Japan, and Australia have shown more recent signs of slowdowns, flat growth, and somewhat volatile emissions trajectories as they pursue a range of different climate and energy policies in recent years.

Still, the pressure is on. In 101 countries, representing 50% of global CO₂ emissions, emissions increased as economies grew. Many of these countries will be pursuing economic development for years to come.

Contrasting fortunes among some of the world’s biggest economies.
Nigel Hawtin/Future Earth Media Lab/Global Carbon Project, Author provided

A peek into the future

During the three-year emissions “plateau” – and specifically in 2015-16 – the accumulation of CO₂ in the atmosphere grew at a record high that had not previously been observed in the half-century for which measurements exist.

It is well known that during El Niño years such as 2015-16, when global temperatures are higher, the capacity of terrestrial ecosystems to take up CO₂ (the “land sink”) diminishes, and atmospheric CO₂ growth increases as a result.

The El Niño boosted temperatures by roughly a further 0.2℃. Combined with record high levels of fossil fuel emissions, the atmospheric CO₂ concentration grew at a record rate of nearly 3 parts per million per year.

This event illustrates the sensitivity of natural systems to global warming. Although a hot El Niño might not be the same as a sustained warmer climate, it nevertheless serves as a warning of the global warming in store, and underscores the importance of continuing to monitor changes in the Earth system.

The effect of the strong 2015-16 El Niño on the growth of atmospheric CO₂ can clearly be seen.
Nigel Hawtin/Future Earth Media Lab/Global Carbon Project, based on Peters et al., Nature Climate Change 2017, Author provided

No room for complacency

There is no doubt that progress has been made in decoupling economic activity from CO₂ emissions. A number of central and northern European countries and the US have shown how it is indeed possible to grow an economy while reducing emissions.

Other positive signs from our analysis include the 14% per year growth of global renewable energy (largely solar and wind) – albeit from a low base – and the fact that global coal consumption is still below its 2014 peak.


Read more: World greenhouse gas levels made unprecedented leap in 2016


These trends, and the resolute commitment of many countries to make the Paris Agreement a success, suggest that CO₂ emissions may not return to the high-growth rates experienced in the 2000s. However, an actual decline in global emissions might still be beyond our immediate reach, especially given projections for stronger economic growth in 2018.

The ConversationTo stabilise our climate at well below 2℃ of global warming, the elusive peak in global emissions needs to be reached as soon as possible, before quickly setting into motion the great decline in emissions needed to reach zero net emissions by around 2050.

Pep Canadell, CSIRO Scientist, and Executive Director of the Global Carbon Project, CSIRO; Corinne Le Quéré, Professor, Tyndall Centre for Climate Change Research, University of East Anglia; Glen Peters, Research Director, Center for International Climate and Environment Research – Oslo; Robbie Andrew, Senior Researcher, Center for International Climate and Environment Research – Oslo; Rob Jackson, Chair, Department of Earth System Science, and Chair of the Global Carbon Project, globalcarbonproject.org, Stanford University, and Vanessa Haverd, Senior research scientist, CSIRO

This article was originally published on The Conversation. Read the original article.

Growth in fossil fuel emissions slowed in 2015, so have we finally reached the peak?


Pep Canadell, CSIRO

Despite robust global economic growth over the past two years, worldwide carbon emissions from fossil fuels grew very little in 2014, and might even fall this year.

A report released today by the Global Carbon Project has found that fossil fuel emissions of carbon dioxide grew by only 0.6% in 2014, breaking with the fast emissions growth of 2-3% per year since early 2000s. Even more unexpectedly, emissions are projected to decline slightly in 2015 with continuation of global economic growth above 3% in Gross Domestic Product.

This is the first two-year period in a multi-decade record where the global economy shows clear signs of decoupling from fossil fuel emissions. In the past, every single break or decline in the growth of carbon emissions was directly correlated with a downturn in the global or regional economy.

This time is different.

However, it is quite unlikely that 2015 is the much-sought-after global peak in emissions which will lead us down the decarbonisation path required to stabilise the climate.

In a separate paper published today in Nature Climate Change, we look in more detail at the possibility of reaching global peak emissions.


Future Earth/Global Carbon Project

What caused it?

The principal cause of this unexpected lack of growth in emissions is the slowdown in the production and consumption of coal-based energy in China in 2014, followed by a decline in 2015.

This has taken China’s emissions growth from close to double digits during the past decade to an extraordinary low of 1.2% growth in 2014 and an unexpected decline by about 4% projected for 2015.

Although China is only responsible for 27% of global emissions, it has dominated the growth in global emissions since early 2000s. Therefore, a slowdown in China’s emissions has an immediate global impact.

Further adding to this main cause, emissions from industrialised economies, including Australia, Europe and the United States, have declined by 1.3% per year on average over the past decade, partially supported by extraordinary growth of renewable energy sources.

In the past every time emissions have fallen has been associated with economic recession.
CSIRO/Global Carbon Project

Have we reached global peak emissions?

Most likely not. One key uncertainty in answering this question is the future of coal in China. But China is pushing to achieve peak carbon consumption as early as possible (and emissions by 2030), and to phase out the dirtiest types of coal from the nation’s energy mix, largely in response to a pollution crisis affecting many of its large urban areas. It is well within the possibilities that growth in coal emissions in China will not resume any time soon, and certainly not at the fast pace of the previous decade.

A strong basis for this assessment is the remarkable growth in non-fossil fuel energy sources such as hydro, nuclear and renewables. These accounted for more than half of the growth in new energy in 2014, with a very similar mix during the first three-quarters of this year. Such structural changes, if continued, could bring China’s peak emissions much earlier than anyone is anticipating and certainly well before 2030.

Although it is unlikely that we have reached global peak emissions, it is very likely that 2015 marks a new era of slower growth in fossil fuel emissions. This is perhaps the first sign of a looming peak on a not-too-distant horizon.

Where from here?

Recent modelling analyses of post-2020 pledges by over 180 countries to reduce emissions to 2030 (the so-called Intended Nationally Determined Contributions) show that peak emissions is not to come any time soon. Under the pledges made, global emissions continue to rise to 2030.

This might well be the future. But models used for such analysis were not that different from those that completely missed the very rapid rise of the Chinese economy in the decade of 2000 and perhaps now its rapid decarbonisation.

However, China is not alone in this game. Industrialised countries plus China, accounting for half of global fossil fuel emissions, have pledged to reduce or stabilise emissions absolutely by 2030.

But the other half belongs to less-developed nations whose pledges do not include absolute emission reductions but departures from business-as-usual scenarios (meaning emissions can increase, but not as fast). This emphasises the disproportionate importance of international climate finances required to help that “other” half of the emissions to peak and join the decline of the rest.

2015 has been an extraordinary year, and not just because of China. Emissions from Australia, Europe, Japan and Russia have all come down as part of longer or more recent trends. Installed wind capacity reached 51 gigawatts in 2014, an amount greater than the total global wind capacity just a decade ago. Solar capacity is 50 times bigger than it was ten years ago.

And emissions from land-use change, albeit with large uncertainties and high emissions from Indonesian fires this year, have been on a declining trend for over a decade. These trends are not stopping here.

Yet the current emissions path is not consistent with stabilising the climate at a level below 2℃ global warming.

If we maintain the level of 2015 emissions, the remaining carbon budget before setting the earth on a path that exceeds 2℃ is less than 30 years away, unless we bet on unproven negative emissions technologies to remove carbon from the atmosphere later in the century.

But 2015 is a historic year to galvanise further action. The trends in emissions are favourable, and countries have the opportunity to negotiate significantly higher levels of ambition to decouple economic growth from emissions.

The Conversation

Pep Canadell, CSIRO Scientist, and Executive Director of Global Carbon Project, CSIRO

This article was originally published on The Conversation. Read the original article.

Deserts Growth Spurt


The link below is to an article that reports on the growth explosion in deserts due to the increase in CO2.

For more visit:
http://www.natureworldnews.com/articles/2871/20130709/increasing-carbon-dioxide-levels-causing-desert-bloom-study.htm