Australia’s 2017 environment scorecard: like a broken record, high temperatures further stress our ecosystems



File 20180407 5587 1mogxms.png?ixlib=rb 1.1
It was a hot year for many Australians.
ABCNews/David McMeekin

Albert Van Dijk, Australian National University and Madeleine Cahill, CSIRO

While rainfall conditions were generally good across Australia in 2017, record-breaking temperatures stressed our ecosystems on land and sea, according to our annual environmental scorecard. Unfortunately, it looks like those records will be broken again next year – and again in the years after that.

Indicators of Australia’s environment in 2017 compared to the previous year. Similar to national economic indicators they provide a summary, but also hide regional variations, complex interactions and long-term context.

National Scorecard

Our terrestrial environment has done relatively well in 2017, mainly thanks to good rainfall and leftover soil moisture from the year before. However, such a short summary for a country the size of a continent is bound to hide large regional differences. 2017 was no exception.

Western Australia and the Northern Territory received good rains, with vegetation growth, river flows and wetland area all coming in above average. By contrast, Queensland and particularly New South Wales saw a reversal of the previous year’s gains.

Environmental Condition Score in 2017 by state and territory. The large number is the score for 2017, the smaller number the change from the previous year.
Based on data on http://www.ausenv.online

Climate change is here to stay

There was good news and bad news for our atmosphere in 2017. Humanity’s collective action to fix the hole in the ozone layer is proving successful. The hole is the smallest it has been since 1988.

On the other hand, global carbon dioxide concentrations rose again, by 0.5%. While this was less than in the previous two years, it was still far from enough to stop accelerating global warming.

Globally, 2017 was the second-warmest year on record after 2016. It was the third-warmest year for Australia, and the hottest year on record in southern Queensland. These statistics are all the more remarkable because 2017 was not an El Niño year, during which high temperatures more commonly occur.

The world’s oceans were the hottest they’ve been since measurements started. Sea levels rose by 6.4mm, and sea ice cover at the poles reached another record low. In short, our planet is warming.




Read more:
Climate change’s signature was writ large on Australia’s crazy summer of 2017


The main events

Last year broke the most high-temperature records since 2009, which was at the height of the Millennium Drought – the worst drought since European settlement.

Queensland and northern New South Wales were affected most, with summer heatwaves in February and a second round of bleaching on the Great Barrier Reef. In March, Cyclone Debbie rammed into the Great Barrier Reef and the Queensland coast, bringing torrential rains and widespread flooding in its wake. The cyclone helped cool down the shallow reef waters but also ravaged delicate corals in its path, stirred up sediment and caused rivers to flush more damaging sediment and nutrients out to sea.

Winter was dry and the warmest on record and September also set heat records. Experts predicted the risk of a bad summer fire season, which did not happen, thanks to a combination of mild weather and well-timed rainfall. Nationally though, the number and size of fires were still above average, mainly due to good growing conditions in WA’s arid rangelands.

Tree growth hides loss of forests

Perhaps the most recognisable impact on our terrestrial ecosystems is the disappearance of mature vegetation after fire, drought or land clearing. We should have good data on such important changes, but we don’t.

Australia is large and poorly surveyed, so national mapping relies on satellite image interpretation. We used machine-learning algorithms to update national forest maps with more recent satellite images. These updated maps estimate a nationwide increase in forest area of 510,000ha, roughly the size of Kangaroo Island.

However, this increase is the difference between much larger gains and losses. Most of the forest increases occurred in dry woodlands in NSW and Queensland, most likely due to regrowth after a relatively wet 2016.

Unfortunately, these numbers do not paint a clear picture of the state of our ecosystems. Far more is lost from removing a hectare of dense native forest than is gained from a hectare of regrowth or new planting.

The current national mapping is insufficient to make these distinctions. We now have the satellite mapping data and technologies to do a better job. This should be a priority if we are to understand how our environment is changing and meet our international commitments.

Australia’s Environment Explorer (http://www.ausenv.online) provides summaries of environmental condition by location or region. This example shows local government areas where vegetation cover in 2017 was above average (blue colours) or below average (red colours).

Slow changes can still be deadly

While our climate is clearly changing, it is less clear how rising temperatures are impacting on our ecosystems. Many of our species are well adapted to heat, so the effects of slowly rising temperatures may go unnoticed until it is too late.

Temperatures in excess of 42℃ can kill large numbers of flying foxes, and this happened again in 2017. We know this because they roost together in their thousands and we can count the corpses under the trees.

What heat stress does to other species is far less known. There is evidence of koalas and some large birds suffering from hot days, but we barely understand how increasing temperatures may be chipping away at the cornerstones of our ecosystems: plants, bacteria, fungi, insects and other uncharismatic creatures.

At sea, we can see the impact of high sea temperatures through coral bleaching, visible even from space. Sea surface temperatures also reached record highs off the coast of southeast Australia for the second year in a row.

On top of the steady rise of ocean temperature, sea level and acidity, the East Australian Current is strengthening and reaching ever further into the Tasman Sea. The current carries tropical reef species to Sydney and yellowtail kingfish to Tasmania. The warmer water also ravages the remaining kelp forests and stresses Tasmania’s abalone, oyster and salmon industries.

The future is already here

Last year made it abundantly clear that climate change is here now, and here to stay. We will be seeing new heat records for years to come and, sadly, some species and ecosystems are unlikely to survive the onslaught.

But there are still things we can do to limit the damage. Reducing carbon emissions will still help limit future warming. Avoiding the destruction of native ecosystems should be a no-brainer.

That isn’t just about clearing farm land, which is often singled out. Australia’s population has grown by 31% since 2000. We’re adding the equivalent of a city the size of Canberra every year.

The ConversationEach of us uses space, infrastructure and resources and produces waste at levels far above the global average. If we want our land and oceans to support our privileged lifestyle in future, we have to learn to tread more lightly, and learn it fast.

Albert Van Dijk, Professor, Water and Landscape Dynamics, Fenner School of Environment & Society, Australian National University and Madeleine Cahill, Oceanographer, CSIRO

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

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Australia’s climate in 2017: a warm year, with a wet start and finish


Linden Ashcroft, Australian Bureau of Meteorology; Blair Trewin, Australian Bureau of Meteorology, and Skie Tobin, Australian Bureau of Meteorology

The Bureau of Meterology’s Annual Climate Statement, released today, confirms that 2017 was Australia’s third-warmest year on record, and our maximum temperature was the second-warmest. Globally, 2017 is likely to be one of the world’s three warmest years on record, and the warmest year without an El Niño.


Read more: Explainer: El Niño and La Niña


But looking at the big picture can obscure some regional record-breaking features. Victoria experienced its driest June on record, and September saw New South Wales and the Murray–Darling Basin record their driest September since nationwide records begin in 1900. Sydney’s Observatory Hill had its driest September since records started there in 1858.

The southwest of Western Australia had its warmest maximum temperatures on record for June. Northern Australia also recorded its warmest dry season for maximum temperature.

A field in Moree, New South Wales. The state had its driest September on record.
Bureau of Meteorology, Author provided

This warm year occurred despite the fact that, unlike 2016, there was no strong El Niño or La Niña pattern in the Pacific Ocean for much of the year, and the Indian Ocean Dipole remained neutral.


Read more: What is the Indian Ocean Dipole?


Wet in the northwest, dry in the east

Australia’s average total rainfall in 2017 was 504mm, somewhat above average. But the annual average hides large swings from very dry months to damaging downpours, and large differences from the east to the west of the country.

The year began wet, particularly in the west. Tropical lows brought heavy rainfall across the Northern Territory, South Australia and Western Australia during January and February, and many places in Western Australia set new records for their wettest summer day. It was our fourth-wettest January on record nationally.

Severe Tropical Cyclone Debbie crossed the south Queensland coast in late March and tracked southwards delivering torrential rainfall along the east coast. Several locations received up to a metre of rainfall in two days, and major flooding occurred from Bowen, in Queensland, to Lismore, in New South Wales.

The west of Western Australia was dry for much of autumn and early winter. Winter rainfall was also low across southern Australia under the effect of a subtropical ridge stronger and further south than usual.

Heavy rain across much of Queensland and northern New South Wales during October meant that Bundaberg received more than 400% of its average rainfall for October in the first three weeks of the month.

In late December, Tropical Cyclone Hilda became the first cyclone to make landfall in the 2017-18 Australian cyclone season, bringing heavy rains around Broome.

Australia’s rainfall in 2017.
Bureau of Meteorology, Author provided

A hot start

It might not have always felt like it, but 2017 was much warmer than average. It was the third-warmest year on record for Australia, 0.95℃ above average, and the warmest on record for Queensland and New South Wales. Sea surface temperatures were also much warmer than average around Australia, although not as warm as 2016.

Australia’s average temperatures in 2017.
Bureau of Meteorology, Author provided

New South Wales experienced its warmest summer on record, and heatwaves affected much of eastern Australia during the first two months of the year. At the same time, rain kept summer temperatures below average in the west.

The high temperatures around eastern Australia continued into autumn, over both land and sea. Coral bleaching affected the Great Barrier Reef again, the first time mass bleaching events have occurred in consecutive years.

Warm days but chilly winter nights

As winter set in, the lack of rainfall and clouds led to warm sunny days. The southwest of Western Australia had its warmest maximum temperatures on record for June.


Read more: Australia’s record-breaking winter warmth linked to climate change


However the clear skies also meant frosty mornings across much of Victoria, southern New South Wales, South Australia and Tasmania. Canberra, which is known for its chilly nights, had its lowest winter mean minimum temperature since 1982. Some locations, including Sale in Victoria, and Deniliquin and West Wyalong in New South Wales, had their coldest night on record during the first few days of July.

Meanwhile, northern Australia recorded its warmest dry season on record for maximum temperature. The mean maximum temperature for northern Australia was 2℃ above average for the five months from May to September, beating the previous record set in 2013 by almost half a degree.

A warm finish

In September, northerly air flow brought the warm air over to the east of the country, with the month culminating in a week of exceptional heat. New South Wales recorded its first ever 40℃ in September – not once, but on two separate days – and some places beat their previous hottest September day on record by more than 3 degrees.

Late-season frosts in early November caused damage to crops in western Victoria, but the cold was soon replaced by prolonged heat thanks to a slow moving high pressure system parked over the Tasman Sea.

The northerly winds and sunny days meant that many places in Victoria and Tasmania had record runs of days warmer than 25℃, and nights warmer than 15℃. It was Tasmania’s warmest November on record, with temperatures more typical of late summer than late spring.

The long-lived weather system led to record-breaking November sea surface temperatures between Tasmania and New Zealand, which also had a very warm and dry November. The southeast of the country finished 2017 with our first heatwave of the summer in mid-December.

The bigger picture

Global mean temperature anomalies relative to 1961-1990, 1880–2017.
Bureau of Meteorology, Author provided

The World Meteorological Organization releases the final global mean temperature for 2017 in mid-January. This enables it to collect as many observations as possible from different countries. But the January to November global average can give a pretty good idea of where 2017 will sit: one of the world’s three warmest years on record.

The planet has seen plenty of extreme weather events over the past year, including hurricanes, flooding, and devastating bushfires.

The ConversationGlobal temperatures have increased by about one degree since 1900. Mean global temperatures have been above average every year since 1985, and all of the ten warmest years have occurred between 1998 and the present. Seven of Australia’s ten warmest years have now occurred since 2005.

Linden Ashcroft, Climatologist, Australian Bureau of Meteorology; Blair Trewin, Climate scientist, Australian Bureau of Meteorology, and Skie Tobin, Climatologist, Australian Bureau of Meteorology

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

2017: the year in extreme weather


Andrew King, University of Melbourne

Overall 2017 will be the warmest non-El Niño year on record globally, and over the past 12 months we have seen plenty of extreme weather, both here in Australia and across the world.

Here I’ll round up some of this year’s wild weather, and look forward to 2018 to see what’s around the corner.

Drought and flooding rains… again

It feels as if Australia has had all manner of extreme weather events in 2017.
We had severe heat at both the start and end of the year. Casting our minds back to last summer, both Sydney and Brisbane experienced their hottest summers on record, while parts of inland New South Wales and Queensland endured extended periods of very high temperatures.


Read more: We’ve learned a lot about heatwaves, but we’re still just warming up


More recently Australia had an unusually dry June and its warmest winter daytime temperatures on record. The record winter warmth was made substantially more likely by human-caused climate change.

The end of the year brought more than its fair share of extreme weather, especially in the southeast. Tasmania had by far its warmest November on record, beating the previous statewide record by more than half a degree. Melbourne had a topsy-turvy November with temperatures not hitting the 20℃ mark until the 9th, but a record 12 days above 30℃ after that.

November was rounded off by warnings for very severe weather that was forecast to strike Victoria. Melbourne missed the worst of the rains, although it still had a very wet weekend on December 2-3. Meanwhile, northern parts of the state were deluged, with many places recording two or three times the December average rainfall in just a couple of days.

Hurricane after hurricane after hurricane…

Elsewhere in the world there was plenty more headline-worthy weather.

The Atlantic Ocean had a particularly active hurricane season, with several intense systems. Hurricane Harvey struck Texas and its slow trajectory resulted in record-breaking rainfall over Houston and neighbouring areas.

Then Hurricanes Irma and Maria, both of which reached the strongest Category 5 status, brought severe weather to the Caribbean and southeastern United States just a couple of weeks apart. Island nations and territories in the region are still recovering from the devastation.

Around the same time, the Indian subcontinent experienced a particularly wet monsoon season. Flooding in India, Pakistan, Bangladesh, and Nepal killed more than 1,000 people and affected tens of millions more.

Other parts of the world experienced their own severe weather events. Whether it was summer heat in Europe or wildfires in California, 2017 dished up plenty of extremes.

In many cases, especially for heat extremes, we can rapidly identify a human influence and show that climate change is increasing the frequency and intensity of such events.

For other weather types, like the very active hurricane season and other extreme rain or drought events, it is harder (but not always impossible) to work out whether it bears the fingerprint of climate change.

What’s in store for 2018?

The main problem when trying to offer an outlook is that extreme weather is hard to predict, even on the scale of days or weeks in advance, let alone months.

For Australia, with a weak La Niña in the Pacific, there are few clear indications of what the rest of the summer’s weather will bring. There is a suggestion that we can expect a slightly wetter than average start to the year in parts of the southeast, along with warmer than average conditions for Victoria and Tasmania. Beyond that it is anyone’s guess.


Read more: Not just heat: even our spring frosts can bear the fingerprint of climate change


The La Niña is also likely to mean that 2018 won’t be a record hot year for the globe. But it’s a safe bet that despite the La Niña, 2018 will still end up among the warmest years on record, alongside every other year this century. Rising global average temperatures, along with our understanding of the effect of greenhouse gas emissions, are one of our clearest lines of evidence for human-caused climate change.

The ConversationSo it’s hard to say much about what extreme weather we’ll experience in 2018, other than to say that there’s likely to be plenty more weather news to wrap up in a year’s time.

Andrew King, Climate Extremes Research Fellow, University of Melbourne

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

Doom and gloom? Here are the environment stories that cheered us up in 2017


Madeleine De Gabriele, The Conversation and Michael Hopkin, The Conversation

Don’t let anyone tell you we’re not a cheerful bunch here on the Environment + Energy desk – even if many of the stories we cover are a little on the gloomy side.

From the Great Barrier Reef to the Australian outback, and from Canberra to the White House, it’s been another less than stellar year for the environment.

That said, the soap opera over energy policy kept us pretty entertained in the meantime.

But that doesn’t mean there aren’t plenty of positive, amazing and ridiculous stories out there. So for some festive cheer, here are some good news stories we covered in 2017, and a few more we would have liked to have had room for alongside the heatwaves and political hot air.

Parrots on a flyer

Rare parrots had some rare wins this year. A night parrot was photographed for the first time in Western Australia. For a bird that’s so secretive it was previously assumed by many people not to exist, that’s a solid result.

Meanwhile, scientists in Tasmania developed amazing automatic light-sensitive doors to protect the swift parrots’ nest boxes (the excellently named “possum-keeper-outer”).

Boxing clever.
ANU
Keep out, sugar gliders.
ANU

Yoghurt-pot-washers rejoice

If you’ve invested an inadvisable amount of your free time in washing scraps of food off cans, containers and bottles before tossing them straight into the recycling, then suffer no longer. In May we reported the exciting news that most recycling facilities can handle a bit of mess.

Our Facebook page rang to the joyous strains of readers gleefully telling their parents/partners/housemates to stop nagging and let them enjoy the sweet freedom from the tyrannical regime of spotless peanut butter jars.

Hoodwinked no longer

Have you ever discovered a never-before-seen fish species that can grow larger than a very large human? Of course you haven’t. But Murdoch University’s Marianne Nyegaard has.

Beachcombing: expert level.
Marianne Nyegaard/Murdoch University

Starting with some tantalising DNA evidence that suggested there was a new species of sunfish somewhere out there, she embarked on a four-year detective mission. After a tip-off she eventually found four of them washed up on a beach near Christchurch, and named the species Mola tecta – the “hoodwinker sunfish” – in honour of its long-running disappearing trick.

When little kids say they want to be a marine biologist when they grow up, this is exactly what they mean.

We used some fancy new words

The interminable politicking over energy policy, including the Finkel Review and the National Energy Guarantee, made us want to pull our hair out at times. But look on the bright side: the endless debate brought previously obscure terms such as dispatchables, baseload, spinning reserve, inertia, and frequency control into common parlance.

As energy nerds, we’re super excited that all this stuff finally went mainstream in 2017. It’s made us so much more fun to talk to at parties. But after thinking about dispatchable energy all year, we kind of wish someone would dispatch us a stiff drink.

Whisky wonder

Speaking of which, it turns out that it’s possible to make a ten-year malt whisky in a matter of weeks, because chemistry loves us and wants us to be happy.

Swoop on this

Just as exciting is the news that you can make friends with your local magpies, with the help of some judiciously offered food. And because magpies are so smart, once you gain their trust they’ll remember you forever, with obvious benefits when swooping season rolls around.

They’re apparently partial to mince, and while it might seem eccentric to carry it around in your pockets, you’ll reap the rewards when the maggies aren’t making mincemeat out of your ears next spring.


Meanwhile, here are some other cheery developments we didn’t have space for this year.

Snow leopards on the comeback trail

A three-year survey that concluded in September found at least 4,000 snow leopards in the wild, moving the elusive big cats off the IUCN endangered list for the first time in 44 years.

While it’s not all sunshine – snow leopards are still considered “vulnerable” and face considerable challenges with poaching and habitat loss – population numbers aren’t declining as sharply as previously thought, and scientists say there could be as many as 10,000 prowling the Himalayas.

I, for one, welcome our cephalopod overlords

In absolutely stunning footage, David Attenborogh’s Blue Planet II captured an octopus using shells to disguise itself from a shark. A dexterous animal using tools to outwit a more deadly predator? Sounds familiar.

When you combine this video with reports of dozens of octopuses crawling out of the ocean onto a British beach, it might be time to get worried. The good news is that they seem to be invading Wales first.

Noisy neighbours

Nature is cool, if not always quiet. Scientists described a kind of shrimp (named after Pink Floyd) that can kill its prey with concussive sound.

Meanwhile, another study found that orgies of Mexican fish are deafening dolphins. On reflection, this is probably only good news for the fish.

Check out this spider, man

Closer to home, and considerably more quiet, a new species of jumping spider has been found on the Cape York Peninsula.

What’s in a name?
BushBlitz

The ConversationIn a fit of unwarranted optimism, the naming of this spider has been thrown open to the public. It’s a safe bet that most of the 700 submissions will turn out to be unprintable, improbable, or unimaginative variations on Spidey McSpideyface.

Madeleine De Gabriele, Deputy Editor: Energy + Environment, The Conversation and Michael Hopkin, Section Editor: Energy + Environment, The Conversation

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.

2017 is set to be among the three hottest years on record


Andrew King, University of Melbourne and David Karoly, University of Melbourne

The year isn’t over yet, but we can already be sure that 2017 will be among the hottest years on record for the globe. While the global average surface temperature won’t match what we saw in 2016, it is now very likely that it will be one of the three warmest years on record, according to a statement issued by the World Meteorological Organization.

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What is more remarkable is that this year’s warmth comes without a boost from El Niño. When an El Niño brings warm waters to the tropical east Pacific, we see a transfer of heat from the ocean to the lower atmosphere, which can raise the global average temperatures recorded at the surface by an extra 0.1-0.2℃. But this year’s temperatures have been high even in the absence of this phenomenon.


Read more: Why hot weather records continue to tumble worldwide


We can already say with confidence that 2017 will end up being the warmest non-El Niño year on record, and that it will be warmer than any year before 2015. The average global temperature between January to September this year was roughly 1.1℃ warmer than the pre-industrial average.

This trend is associated with increased greenhouse gas concentrations, and this year we have seen record high global atmospheric carbon dioxide concentrations and the biggest recorded surge in CO₂ levels.

A year of extremes

Of course, none of us experiences the global average temperature, so we also care about local extreme weather. This year has already seen plenty of extremes.

Global sea ice extent continues to decline.
NASA Earth Observatory

At the poles we’ve seen a continuation of the global trend towards reduced sea ice extent. On February 13, global sea ice extent reached its lowest point on record, amid a record low winter for Arctic ice. Since then the Arctic sea ice extent has become less unusual but it still remains well below the satellite-era average. Antarctic sea ice extent also remains low but is no longer at record low levels as it was in February and March of this year.

East Africa saw continued drought with failure of the long rains, coupled with political instability, leading to food insecurity and population displacement, particularly in Somalia.

Storms and fires

This year also saw a very active North Atlantic hurricane season. Parts of the southern United States and the Caribbean were struck by major hurricanes such as Harvey, Irma, and Maria, and are still recovering from the effects.

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Other parts of the globe have seen a quieter year for tropical cyclones.

There have also been several notable wildfire outbreaks around the world this year. In Western Europe, record June heat and very dry conditions gave rise to severe fires in Portugal. This was followed by more severe fires across Spain and Portugal in October.


Read more: Wildfires are raging in the Mediterranean. What can we learn?


Parts of California also experienced severe fires following a wet winter, which promoted plant growth, and then a hot dry summer.

Australia is now gearing up for what is forecast to be a worse-than-average fire season after record winter daytime temperatures. A potential La Niña forming in the Pacific and recent rains in eastern Australia may reduce some of the bushfire risk.

The overall message

So what conclusions can we draw from this year’s extreme weather? It’s certainly clear that humans are warming the climate and increasing the chances of some of the extreme weather we’ve seem in 2017. In particular, many of this year’s heatwaves and hot spells have already been linked to human-caused climate change.

For other events the human influence is harder to determine. For example, the human fingerprint on East Africa’s drought is uncertain. It is also hard to say exactly how climate change is influencing tropical cyclones, beyond the fact that their impact is likely to be made worse by rising sea levels.

The ConversationFor much of 2017’s extreme weather, however, we can say that it is an indicator of what’s to come.

Andrew King, Climate Extremes Research Fellow, University of Melbourne and David Karoly, Professor of Atmospheric Science, University of Melbourne

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