Lethal Heating: 02/23/16

23/02/2016

Fossil Fuel Emissions Behind Australia's Record-Breaking Spring Heat, Suggests Study

The Guardian - Graham Readfearn

Scientists say it is highly likely greenhouse gas emissions are behind Australia's run of three hottest springs on record - 2014, 2015 and 2013

Leanne Brow inspects the remains of her home in Winmalee, New South Wales, following severe bush fires in October 2013, one of Australia's hottest springs on record. Photograph: Lisa Maree Williams/Getty Images

World leaders and street protesters were struggling in a heatwave with temperatures hovering around 40C at Brisbane’s G20 meeting.
Longreach in central Queensland had 13 days straight when the maximum temperature hit 40C (104F) or higher – four days longer than the town’s previous record.
Down in New South Wales and Tasmania, residents fought off bushfires. A few weeks earlier, South Australia had its hottest October on record.
This was the spring of 2014, Australia’s hottest September-November period on a record going back to 1910, beating the previous record by a 10th of a degree – a large margin in climatological terms.
“Temperatures were 1.67C above the 1961–1990 average, the largest such departure from the long-term average observed since national records began in 1910,” the Bureau of Meteorology said.
These sorts of spring conditions are perfect for priming bush areas for dangerous fire seasons (extreme fire weather is on the rise in Australia) that damage property, risk lives and devastate wilderness areas.
But the spring of 2014 had been the second record breaker in a row. The previous hottest spring had been the year before, 2013.
There had never been two record-breaking springs occurring back-to-back in Australia’s entire record, going back to 1910.
The most recent spring of 2015 was hotter than 2013, but not quite as hot as 2014. The hottest October on record was the one we just had.
So springs in Australia are starting to feel like summer, but could the so-called “lucky country” just be having a run of bad luck?
If there had not been about 40% more carbon dioxide in the atmosphere now than there had been before the start of the industrial revolution, could Australians have still sweated through record-breaking springs?
A new study in the journal Geophysical Research Letters by Dr Ailie Gallant, of Monash University, and Dr Sophie Lewis, of Australian National University, has come to a conclusion.
Gallant told me:

When we examined a world without human-emitted greenhouse gases in climate models, we found zero instances when there were two consecutive years with record-breaking springtime temperatures like those we observed in 2013 and 2014.
But when we examined a world with these additional greenhouse gases, we saw that this happened somewhere between 1 in every 10 years and one in every four. This evidence suggests that this repeated record breaking that we saw in spring in 2013 and 2014, and again in 2015, is almost certainly due to greenhouse warming.

Now this isn’t a surprising outcome. Australia has been warming at roughly the same rate as the rest of the globe, and the cause is the greenhouse gases accumulating in the atmosphere, mainly from burning fossil fuels.
Previous studies have found human fingerprints all over Australia’s recent heat records.
To carry out the study, Gallant and Lewis combined computer climate models. They ran the models to see if the results they gave matched what was happening in the real world. The differences were “statistically indistinguishable”.
To see what impact greenhouse gases were having, they then removed the greenhouse gases from the models to make a comparison.
What makes the study intriguing is that it not only tried to answer the question of the impacts of greenhouse gas emissions, but also looked to find out exactly how they were affecting temperatures. Gallant says:

We had just had two hot springs in a row and we were set for a third. They were really remarkable. They broke records by a long way. We wanted to know; is the weather we are experiencing changing, or is it just that we’ve warmed up.
The evidence is that the underlying air masses are warming, rather than the systems themselves changing.
We are getting more record hot springs and it is highly unlikely that this is not due to climate change. But the reason we are getting more record hot springs is not because the weather systems are changing, it is just that everything is warmer.

The study found the natural background conditions (such as atmospheric circulations and the state of the El Niño/La Niña cycle) that existed during those record-breaking springs “have occurred in the past” yet temperatures had been at least 0.21C cooler.
If the dignitaries at that Brisbane G20 meeting were wondering why they were struggling in such oppressive heat, then it seems they had the answer right in their hands.

Links

Bill Gates' Letter To High Schoolers: We Need An 'Energy Miracle' To Stop Climate Change

Business Insider - Jillian D'Onfro

Ramin Talaie/Getty Images

Bill Gates has published his annual letter on behalf of the Bill and Melinda Gates Foundation, and for the first time, he directs it specifically at high school students.
While last year’s letter focused on eradicating disease, this year’s note takes on the topic of energy, and he directs it at young people because he believes they will be the ones responsible for coming up with the “crazy-seeming ideas” necessary to combat climate change.
The basic premise of the letter is that many people around the world still don’t have access to electricity. Those people — about 18% of the world’s population — deserve access to cheap, clean energy. But that “clean” part is very important: We need to get carbon dioxide emissions, which drive climate change, down to zero by the end of the century, in order to avoid dramatic, long-term changes to the world’s climate.
Hitting zero will require an “energy miracle,” he says, but that doesn’t mean that it can’t happen. People — like today’s high schoolers — just need to come up with some powerful, economical solutions.
Gates calls for a massive amount of new research:

When I say ‘miracle,’ I don’t mean something that’s impossible. I’ve seen miracles happen before. The personal computer. The Internet. The polio vaccine. None of them happened by chance. They are the result of research and development and the human capacity to innovate.
In this case, however, time is not on our side. Every day we are releasing more and more CO2 into our atmosphere and making our climate change problem even worse. We need a massive amount of research into thousands of new ideas — even ones that might sound a little crazy — if we want to get to zero emissions by the end of this century.

He suggests that he’s excited about new ways to make wind and solar power available to people even at night, on overcast days, or in areas that don’t get much sun or wind ever — like through batteries that have huge storage capacity. He’s also seen ideas for ways to use solar energy to produce fuel.
“We need to try lots of crazy seeming ideas so we can find a few that help us solve the world’s energy challenge,” he writes.

The note, in its entirety, is funny and inspiring; read it here.

Seas Are Rising at Fastest Rate in Last 28 Centuries

New York Times - Justin Gillis

Juan Carlos Sanchez paddled a kayak with his shoes on a flooded street in Miami Beach last year. Credit Lynne Sladky/Associated Press

The worsening of tidal flooding in American coastal communities is largely a consequence of greenhouse gases from human activity, and the problem will grow far worse in coming decades, scientists reported Monday.
Those emissions, primarily from the burning of fossil fuels, are causing the ocean to rise at the fastest rate since at least the founding of ancient Rome, the scientists said. They added that in the absence of human emissions, the ocean surface would be rising less rapidly and might even be falling.
The increasingly routine tidal flooding is making life miserable in places like Miami Beach, Charleston, S.C., and Norfolk, Va., even on sunny days.
Though these types of floods often produce only a foot or two of standing saltwater, they are straining life in many towns by killing lawns and trees, blocking neighborhood streets and clogging storm drains, polluting supplies of freshwater and sometimes stranding entire island communities for hours by overtopping the roads that tie them to the mainland.
Such events are just an early harbinger of the coming damage, the new research suggests.
"I think we need a new way to think about most coastal flooding," said Benjamin H. Strauss, the primary author of one of two related studies released on Monday. "It's not the tide. It's not the wind. It's us. That's true for most of the coastal floods we now experience."
In the second study, scientists reconstructed the level of the sea over time and confirmed that it is most likely rising faster than at any point in 28 centuries, with the rate of increase growing sharply over the past century — largely, they found, because of the warming that scientists have said is almost certainly caused by human emissions.
They also confirmed previous forecasts that if emissions were to continue at a high rate over the next few decades, the ocean could rise as much as three or four feet by 2100.
Experts say the situation would then grow far worse in the 22nd century and beyond, likely requiring the abandonment of many coastal cities.
The findings are yet another indication that the stable climate in which human civilization has flourished for thousands of years, with a largely predictable ocean permitting the growth of great coastal cities, is coming to an end.
"I think we can definitely be confident that sea-level rise is going to continue to accelerate if there's further warming, which inevitably there will be," said Stefan Rahmstorf, a professor of ocean physics at the Potsdam Institute for Climate Impact Research, in Germany, and co-author of one of the papers, published online Monday by an American journal, Proceedings of the National Academy of Sciences.
In a report issued to accompany that scientific paper, a climate research and communications organization in Princeton, N.J., Climate Central, used the new findings to calculate that roughly three-quarters of the tidal flood days now occurring in towns along the East Coast would not be happening in the absence of the rise in the sea level caused by human emissions.
The lead author of that report, Dr. Strauss, said the same was likely true on a global scale, in any coastal community that has had an increase of saltwater flooding in recent decades.
The rise in the sea level contributes only in a limited degree to the huge, disastrous storm surges accompanying hurricanes like Katrina and Sandy. Proportionally, it has a bigger effect on the nuisance floods that can accompany what are known as king tides.
The change in frequency of those tides is striking. For instance, in the decade from 1955 to 1964 at Annapolis, Md., an instrument called a tide gauge measured 32 days of flooding; in the decade from 2005 to 2014, that jumped to 394 days.
Flood days in Charleston jumped from 34 in the earlier decade to 219 in the more recent, and in Key West, Fla., the figure jumped from no flood days in the earlier decade to 32 in the more recent.
The new research was led by Robert E. Kopp, an earth scientist at Rutgers University who has won respect from his colleagues by bringing elaborate statistical techniques to bear on longstanding problems, like understanding the history of the global sea level.
Based on extensive geological evidence, scientists already knew that the sea level rose drastically at the end of the last ice age, by almost 400 feet, causing shorelines to retreat up to a hundred miles in places. They also knew that the sea level had basically stabilized, like the rest of the climate, over the past several thousand years, the period when human civilization arose.
But there were small variations of climate and sea level over that period, and the new paper is the most exhaustive attempt yet to clarify them.
The paper shows the ocean to be extremely sensitive to small fluctuations in the Earth's temperature. The researchers found that when the average global temperature fell by a third of a degree Fahrenheit in the Middle Ages, for instance, the surface of the ocean dropped by about three inches in 400 years. When the climate warmed slightly, that trend reversed.
"Physics tells us that sea-level change and temperature change should go hand-in-hand," Dr. Kopp said. "This new geological record confirms it."
In the 19th century, as the Industrial Revolution took hold, the ocean began to rise briskly, climbing about eight inches since 1880. That sounds small, but it has caused extensive erosion worldwide, costing billions.
Due largely to human emissions, global temperatures have jumped about 1.8 degrees Fahrenheit since the 19th century. The sea is rising at what appears to be an accelerating pace, lately reaching a rate of about a foot per century.
One of the authors of the new paper, Dr. Rahmstorf, had previously published estimates suggesting the sea could rise as much as five or six feet by 2100. But with the improved calculations from the new paper, his latest upper estimate is three to four feet.
That means Dr. Rahmstorf's forecast is now more consistent with calculations issued in 2013 by the Intergovernmental Panel on Climate Change, a United Nations body that periodically reviews and summarizes climate research. That body found that continued high emissions might produce a rise in the sea of 1.7 to 3.2 feet over the 21st century.
In an interview, Dr. Rahmstorf said the rise would eventually reach five feet and far more — the only question was how long it would take. Scientists say the recent climate agreement negotiated in Paris is not remotely ambitious enough to forestall a significant melting of Greenland and Antarctica, though if fully implemented, it may slow the pace somewhat.
"Ice simply melts faster when the temperatures get higher," Dr. Rahmstorf said. "That's just basic physics."