10/01/2020

Earth Posts Second-Hottest Year On Record To Close Out Our Warmest Decade

Washington Post - Andrew Freedman | Jason Samenow

A kangaroo stands on burned land in Lithgow, New South Wales, Australia, on Tuesday. (Brendon Thorne/Bloomberg)
The planet registered its second-hottest year on record in 2019, capping off a five-year period that ranks as the warmest such span in recorded history. In addition, the 2010s will go down in history as the planet’s hottest decade, according to the Copernicus Climate Change Service (C3S), a science initiative of the Europe Union.
The service, which monitors global surface temperatures, determined Earth last year was a full degree warmer (0.6 Celsius) than the 1981-2010 average. This data provides the first comprehensive global look at the state of the climate in 2019, with U.S. agencies such as NASA and the National Oceanic and Atmospheric Administration (NOAA) expected to announce similar results next week.
“2019 has been another exceptionally warm year, in fact the second warmest globally in our data set, with many of the individual months breaking records,” said Carlo Buontempo, head of C3S, in a news release.
The past five years averaged 2 to 2.2 degrees (1.1 to 1.2 Celsius) above preindustrial levels, C3S found. The magnitude of warming puts the planet perilously close to one of the temperature guardrails outlined in the Paris climate agreement, in which policymakers agreed to limit by 2100 global warming to “well below” 3.6 degrees Fahrenheit, or 2 degrees Celsius, above preindustrial levels.
The aspirational goal in the agreement is to hold temperatures to a 2.7-degree increase, or 1.5 Celsius, above preindustrial levels, which is a target favored by the countries considered most vulnerable to climate impacts, such as small island nations.
The rapid warming has occurred as concentrations of carbon dioxide in the atmosphere, a long-lived heat-trapping greenhouse gas, continue to increase. Copernicus cited satellite measurements showing the amount of carbon dioxide in the planet’s atmosphere in 2019 increased by 2.3 parts per million, which was larger than the growth rate in 2018 but below the growth rate of 2.9 ppm in 2015.
Surface air temperature departures from average during 2019. (Copernicus Climate Change Service)
Overall, the amount of carbon dioxide in the atmosphere is now the highest level in human history and probably has not been seen on this planet for 3 million years. However, to meet the Paris targets, the world would need to commit to rapidly slashing carbon emissions at a rate far outside the plans of any of the largest emitters, making the 2.7-degree goal technically possible but politically unlikely.This past year featured numerous climate milestones, most of which indicated human and natural systems are already being buffeted by extensive impacts from relatively low levels of climate change, considering the warming projected to come in the next several decades.
Last year, extreme climate events, such as a searing European heat wave, drove home the urgency of reducing emissions of greenhouse gases. The recent bush fires in Australia charred millions of acres in December, which was that country’s hottest month on record, capping off its hottest and driest year.
Last year was also the warmest summer in the Northern Hemisphere, and Europe had its hottest year on record. Europe also had its hottest December on record as 2019 came to a close.
The year also brought fierce hurricanes that rapidly intensified from weak to monstrous storms — a process in which climate change is thought to play a role. Among them was Hurricane Dorian, which devastated the northwestern Bahamas. In the United States, Alaska experienced record warmth, with an astonishing lack of sea ice in the Bering and Chukchi Seas even during winter.
The year also brought troubling signs that natural systems that serve to store huge quantities of carbon dioxide and methane, the latter being another powerful greenhouse gas, may be faltering as temperatures increase. In December, a federal report indicated the permafrost that rings the Arctic may already be a net source of atmospheric carbon, which would accelerate global warming in what is known as a positive feedback. Raging fires in the Amazon during the year, largely as a result of a pro-development government in Brazil, now threaten to turn the world’s most productive rainforest into a drier, less carbon-rich savanna.

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(AU) Australia's Wildfires And Climate Change Are Making One Another Worse In A Vicious, Devastating Circle

TIME - Tara Law



The hot, dry conditions that primed southeastern Australia’s forest and fields for the bushfires that have been ravaging the country since September are likely to continue, scientists warn — and climate change has likely made the situation much worse.
Over the past few months, the bushfires have already scorched millions of acres, killed two dozen people, and slaughtered an estimated half a billion animals in the country, where it is currently summer. But scientists say that the risk of additional fires remains high. Southeastern Australia has been “abnormally dry” since September, which means that it would need significant rainfall repeatedly over a period of weeks to become damp enough to cut down the risk of fires, says Dan Pydynowski, a senior meteorologist at AccuWeather.
Unfortunately, such prolonged rain does not appear to be imminent in the next few weeks. Although the region experienced some rain early this week, Pydynowski warns that it has “not been impressive” and is not enough to substantially reduce fire risk. Significant rain from Tropical Storm Blake is also not expected to reach the area most affected by the fires.
“Everything is so dry right now, it doesn’t take much for a fire to spark and blow up and spread,” Pydynowski says.
A cemetery recently hit by bushfires near Mogo, New South Wales, on Jan. 5. Adam Ferguson for TIME

Climate scientists warn that the scale and devastation of the wildfires are clear examples of the way climate change can intensify natural disasters.The Australian bushfires were exacerbated by two factors that have a “well-established” link to climate change: heat and dry conditions, says Stefan Rahmstorf, department head at the Potsdam Institute for Climate Impact Research in Germany and a lead author of the United Nations’ Intergovernmental Panel on Climate Change’s Fourth Assessment Report.
In recent years, Australia has experienced long-term dry conditions and exceptionally low rainfall. Scientists say that droughts in the country have gotten worse over recent decades. At the same time, the country has recorded record high temperatures; last summer was the hottest on record for the country.
“Due to enhanced evaporation in warmer temperatures, the vegetation and the soils dry out more quickly,” says Rahmstorf. “So even if the rainfall didn’t change, just the warming in itself would already cause a drying of vegetation and therefore increased fire risk.”
Australian Prime Minister Scott Morrison, who has resisted calls for the country to reduce its carbon emissions, has been accused of deemphasizing the the link between the bushfires and climate change, saying during a November interview that there isn’t “credible scientific evidence” that curbing emissions would diminish the fires.
However, scientists stress that while many sources may ignite fires — including arson — climate change is a major reason why recent the blazes in Australia have been so destructive.
“There are now disingenuous efforts to downplay the clear role of climate change in worsening the intensity and severity of the Australian fires, or to blame ‘arson’ as a way to distract from the growing threat of climate change. These efforts should be called out for what they are: gross climate denial,” Peter Gleick, a climate scientist and co-founder of Pacific Institute in California.
Gleick says that the bushfires are a “very clear example of the links between climate change and extreme weather.” He points out that these fires are very similar to recent highly destructive fires in Brazil and California.
“It’s not a question of whether climate change has caused these fires. Fires start for natural reasons — or for human cause reasons. What we’re seeing is a worsening of the conditions that make the fires in Australia unprecedentedly bad,” says Gleick. “All of these factors — record heat, unprecedented drought, lack of rain — all contribute to drying out the fuel that makes these fires worse. What we have are fires that might have occurred anyway, but the extent, the severity, the intensity of these fires is far worse than it otherwise would have been without the fingerprints of climate change.”
Rahmstorf also says that climate scientists believe wildfire conditions are worsening because climate change affects the water cycle, which in turn “leads to less rainfall in already dry parts of the world, and more rainfall in the already wet parts of the world.” Australia is especially vulnerable to climate change because the continent is already hot and dry; a large swathe of the country is facing increased risk of drought, says Rahmstorf.
Gleick says that the bushfires can have a ripple effect both on the local landscape and on the global climate. Fires can cause “ember storms,” which can lead to additional fires when embers from smaller fires are picked up by the wind.
Fires also add carbon dioxide — a greenhouse gas — into the atmosphere, which can in turn amplify climate change, Gleick says. “Climate change is making these disasters worse, and these disasters are making climate change worse,” says Gleick. “We’ve only seen a tiny fraction of the climate change that we’re going to see in the coming years and the coming decades. If we’re seeing these disasters with a 1 degree warming of the planet so far, and we know that we’re headed for a 1.5 or 2 or 3 degree warming, we can only imagine how bad these disasters are going to get.”

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(AU) BOM Review Shows 2019 Was A Year Of Weather Extremes

ABC Weather - Kate Doyle

The attitude required to get through our hottest and driest year on record. (ABCMyPhoto: Clancy Paine)
From heatwaves and fires to floods and snow, 2019 was a big year of weather.
It wasn't just hot and dry, it smashed the records.
Australia's average maximum daytime temperatures really sizzled — last year was 2.09 degrees Celsius above the 1961-to-1990 average, smashing the previous record by half a degree.
Dr Karl Braganza, the Bureau of Meteorology's head of climate monitoring, said it was the first time an annual anomaly had been two degrees above average.
Annual mean temperatures were also the highest on record for the country as a whole, at 1.52C above average.
There has been a clear upward trend in average temperatures over the past century. (Supplied: Bureau of Meteorology)
It was also Australia's driest year on record, with only 277.6 millimetres of rain for the country on average, 40 per cent less than the long-term average.
Dry years are often hot because rain cools things down, but this is the first time a year has been both the hottest and driest on record.
The previous driest year was 1902, at the end of the federation drought and before the official temperature record began.

2019 wasn't all fire
In Melawondi, near Kandanga and Imbil on the Sunshine Coast, residents collected hailstones in buckets. (Supplied: Bobbie Hamilton)
Major flooding from February to April across western Queensland brought relief to some and devastation to many.
It has been estimated 664,000 cattle died when floodwaters covered much of the Channel and Gulf country.
The on-flow ended with the ephemeral Lake Eyre reaching 65 per cent capacity, its fullest since 2011.
Then, dust storm after dust storm swept across the country along with a number of storm storms that caused havoc — from wrecking the vineyards of South Australia's Riverland to pelting down 11-centimetre hail in Queensland's Wide Bay region.
Widespread snowfall in August feels like a lifetime ago. (ABCMyPhoto: Ross Long)
The south-east of the country was even sprinkled with snow at one point, with the AFL's first snow match in Canberra in August.
Doesn't August feel like a lifetime ago?
But yes, the main story of 2019 was the heat and the fires.
The 2019-20 fire season will forever go down in the record books. (ABCMyPhoto: Martin Von Stoll)
January was plagued by heatwaves, making it Australia's hottest month on record.
Fires burned through Tasmania for weeks, resulting in the state's worst fire season since 1967.
There were also major blazes in Victoria and Western Australia early in the year, only for that devastation to be eclipsed by the recent horror fires.
2019's rainfall was below that of even the millennium drought years. (Supplied: Bureau of Meteorology)
Fires have been raging since September.
On December 17 and then 18, Australia surpassed its hottest day on record — the 19th only missed out on the hat-trick by a whisker.
By the end of December, the BOM's report states more than 5 million hectares have been burnt across Australia since July.
"The extensive long-lived fires appear to be the largest in scale in the modern record in New South Wales, while the total area burnt appears to be the largest in a single recorded fire season for eastern Australia," it said.

Yes, climate change is involved
The majority of Australia recorded rainfall well below average during 2019. (Supplied: Bureau of Meteorology)
The main climate drivers this year were the strongest positive Indian Ocean Dipole (IOD) on record, with a strong negative burst of the Southern Annular Mode (SAM) late in the year.
Both contributed to the hot dry conditions, but this natural variability happens on the foundation of rising temperatures and increasing fire danger for Australia, Dr Braganza said.
"We've got very-well-defined and clear trends, underlying the change that we've seen over the past several decades," he said.
"We've seen clear trends in maximum, minimum and average temperatures across Australia.
"We've seen quite clear trends in reducing rainfall across south-west WA and parts of the south-east."
Red regions indicate where fire weather increased between 1978 and 2017. (Supplied: Bureau of Meteorology )
He said the BOM had also seen a clear trend in fire weather, both in terms of longer and more severe fire seasons.
"The fire season has extended by months in some locations, particularly along the south coast and east Gippsland.
"We're getting more fire weather during the season, and the fire weather we're seeing is more severe.
"That's reflected in heatwaves as well in many parts of the continent."

The year that will be
How 2020 will follow is yet to be determined, but that underlying trend is not going away.
The current outlook is for relatively neutral conditions; the positive IOD broke down as the monsoon moved into the Australian region.
But that doesn't mean we are out of the woods.
"We're not seeing an indication of odds favouring a lot of widespread, above-average rainfall, but we are seeing indications of some rainfall starting to come in with the northern monsoon," Dr Braganza said.
"The hope is that they start to cool down parts of the continent over the central and north-west, which tends to assist in cooling temperatures down a little.
"But really, it's been very hot and dry already. It's still the start of January, there is a deal of summer to go."
Rain and cyclones might finally be coming in the north, but the call is to remain vigilant as the traditionally hottest months of summer are still to come.

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