Stark conclusions seek to empower young to sue for climate justice

Jim Hansen (bottom left) and his family. For their benefit, and for the next generation as a whole, he is pushing for more urgent action on global warming. Credit: James Hansen

Jim Hansen (bottom left) and his family. For their benefit, and for the next generation as a whole, he is pushing for more urgent action on global warming. Credit: JimHansen

Even limiting human-made global climate warming to 2°C above preindustrial temperatures would subject young people, future generations and nature to irreparable harm, leading scientists said on Tuesday. The team led by pioneering climate researcher Jim Hansen, now at Columbia University in New York, calls aiming for this internationally-recognised threshold ‘foolhardy’. In a paper published in PLOS ONE, they outline a case for aiming for 1°C that supports efforts to sue the US government for not doing enough.

“Governments are blatantly failing to do their job,” Jim told me. “They know that human-caused climate change is beginning and poses a huge risk to young people and future generations, and they understand that we must phase out fossil fuel emissions. Yet they go right ahead encouraging companies to go after every fossil fuel that can be found!”

As one of the first climate modellers, Jim has long warned about the greenhouse effect caused by the CO2 we emit from burning fossil fuels. On a sweltering June 23, 1988, he famously testified to the Energy and Natural Resources Committee of the US Senate on the dangers of global warming. “It’s time to stop waffling so much and say that the evidence is pretty strong that the greenhouse effect is here,” he told reporters at the time.

Yet Jim remains frustrated at the slow pace of action, and regularly voices it. In 2006 Mary Wood from the University of Oregon Law School saw one of his articles in the New York Review of Books and contacted him. Her work inspired the formation of a team of lawyers who are suing the US federal government, highlighting the principle that US citizens, young and old, have ‘equal protection of the laws’. “I agreed specifically to write a paper that would provide the scientific basis for legal actions against governments for not doing their job of protecting the rights of young people,” Jim recalled. Read the rest of this entry »

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Fighting for useful climate models

  • This is part two of a two-part post. Read part one here.
Princeton University's Suki Manabe published his latest paper in March this year, 58 years after his first one. Credit: Princeton University

Princeton University’s Suki Manabe published his latest paper in March this year, 58 years after his first one. Credit: Princeton University

When Princeton University’s Syukuro Manabe first studied global warming with general circulation models (GCMs), few other researchers approved. It was the 1970s, computing power was scarce, and the GCMs had grown out of mathematical weather forecasting to become the most complex models available. “Most people thought that it was premature to use a GCM,” ‘Suki’ Manabe told interviewer Paul Edwards in 1998. But over following decades Suki would exploit GCMs widely to examine climate changes ancient and modern, helping make them the vital research tool they are today.

In the 1970s, the world’s weather and climate scientists were building international research links, meeting up to share the latest knowledge and plan their next experiments. Suki’s computer modelling work at Princeton’s Geophysical Fluid Dynamics Laboratory (GFDL) had made his mark on this community, including two notably big steps. He had used dramatically simplified GCMs to simulate the greenhouse effect for the first time, and developed the first such models linking the atmosphere and ocean. And when pioneering climate research organiser Bert Bolin invited Suki to a meeting in Stockholm, Sweden, in 1974, he had already brought these successes together.

Suki and his GFDL teammate Richard Weatherald had worked out how to push their global warming study onto whole world-scale ocean-coupled GCMs. They could now consider geographical differences and indirect effects, for example those due to changes of the distribution of snow and sea ice. Though the oceans in the world they simulated resembled a swamp, shallow and unmoving, they got a reasonably realistic picture of the difference between land and sea temperatures. Their model predicted the Earth’s surface would warm 2.9°C if the amount of CO2 in the air doubled, a figure known as climate sensitivity. That’s right in the middle of today’s very latest 1.5-4.5°C range estimate.

Comparison between the measured sea surface temperature in degrees C calculated by the GFDL ocean-coupled GCM, from a 1975 GARP report chapter Suki wrote - see below for reference.

Comparison between the measured sea surface temperature in degrees C calculated by the GFDL ocean-coupled GCM, from a 1975 GARP report chapter Suki wrote – see below for reference.

At the time no-one else had the computer facilities to run this GCM, and so they focussed on simpler models, and fine details within them. Scientists model climate by splitting Earth’s surface into 3D, grids reaching up into the air. They can then calculate what happens inside each cube and how it affects the surrounding cubes. But some processes are too complex or happen on scales that are too small to simulate completely, and must be replaced by ‘parameterisations’ based on measured data. To get his GCMs to work Suki had made some very simple parameterisations, and that was another worry for other scientists. Read the rest of this entry »

Tundra plants show modern temperatures unmatched in over 44,000 years

Gifford Miller collects vegetation samples on Baffin Island. Credit: University of Colorado, Boulder.

Gifford Miller collects vegetation samples on Baffin Island. Credit: University of Colorado, Boulder.

Tiny plants in Arctic Canada have shown that average summer temperatures there over the last 100 years are higher than those during any century for over 44,000 years. Gifford Miller from the University of Colorado, Boulder, and his teammates collected plants perfectly preserved but recently revealed by rapidly retreating ice sheets. The temperature findings are especially surprising as around 10% more energy from the sun fell on the Northern half of the planet 5,000 years ago than today.  And by looking at other scientists’ historical temperature records, they think the last time temperatures were as warm as today was likely around 120,000 years ago. “This adds to the growing consensus that the greenhouse gases we’ve added to the atmosphere have made a very large difference to the planet’s energy balance,” Gifford told me.

Scientists have known receding glaciers on Baffin Island are revealing well-preserved moss and lichen for almost 50 years. Gifford first read about it during his PhD, which he completed in 1975, in a paper written by a Canadian Department of Mines and Technical Surveys employee in 1966. “I had been to that site in 1981, found where he’d built a camp at the ice edge, measured how far the ice had disappeared and found plants coming out,” he recalled. “I’d repeated what he had done, but hadn’t done anything else with it. But as the ice is melting a lot right now we hypothesised that this wasn’t an isolated case.”

Glaciers don’t usually preserve what’s underneath them. “It’s almost counterintuitive to some people – you think of ice doing some damage to the landscape,” Gifford said. “But ice doesn’t move on its own, it’s driven by gravity. Where it’s flat, there’s not a whole lot of gravity pushing it, and if the ice is fairly thin and cold it’s an exquisite preservation agent. They’re frozen solid when they’re under the ice, which is very cold, like -14°C.” Sites like that can be hard to get to, as many are on plateaus high above Baffin Island. “You could mount climbing expeditions and spend a week getting to one site, so really there’s no practical way to get up there, except to have very good weather and a helicopter,” the scientist added. Read the rest of this entry »

How ocean data helped reveal the climate beast

Wally Broecker's famous quote on display at California Academy of Sciences.  Image copyright: Jinx McCombs, used via Flickr Creative Commons license

Wally Broecker’s famous quote on display at California Academy of Sciences. Image copyright: Jinx McCombs, used via Flickr Creative Commons license

  • This is part two of a two-part post. Read part one here.

On the wall of Wally Broecker’s building at the Lamont-Doherty Earth Observatory hangs a 16-foot long terry-cloth snake, blue with pink spots, that he calls the ‘climate beast’. Left in his office as a surprise by his workmates, its name refers to one of Wally’s most powerful quotes about the climate: “If you’re living with an angry beast, you shouldn’t poke it with a sharp stick.”

Today, the sharp stick is the CO2 we’re emitting by burning fossil fuels, which Wally was warning about by 1975. By that time he had also helped confirm that throughout history, changes in Earth’s orbit have given the climate beast regular kicks, triggering rapid exits from ice ages. He became obsessed with the idea that climate had changed abruptly in the past, and the idea we could provoke the ‘angry beast’ into doing it again.

Among the many samples that Wally was carbon dating, from the late 1950s onwards he was getting treasure from the oceans. Pouring sulphuric acid into seawater, he could convert dissolved carbonate back into CO2 gas that he could then carbon date. And though nuclear weapon tests had previously messed with Wally’s results, they actually turned out to help improved our knowledge of the oceans. The H-bomb tests produced more of the radioactive carbon-14 his technique counts, and as that spike moved through the oceans, Wally could track how fast they absorbed that CO2.

In the 1970s, as Wally and a large team of other scientists sailed on RV Melville and RV Knorr tracking such chemicals across the planet’s oceans, a debate raged. Was cutting down forests releasing more CO2 than burning fossil fuels? Dave Keeling’s measurements showed the amount of CO2 being added to the air was about half the amount produced by fossil fuels. But plants and the oceans could be taking up huge amounts, scientists argued. Thanks to the H-bomb carbon, Wally’s team found the CO2 going into the oceans was just 1/3 of what fossil fuels had emitted. Faster-growing plants therefore seemed to be balancing out the impact of deforestation, and taking up the remaining 1/6 portion of the fossil fuel emissions. Read the rest of this entry »

Bouncing lasers off satellites backs faster Greenland melt

NASA's Goddard Geophysical and Astronomical Observatory in Greenbelt, Maryland, routinely bounces lasers off satellites, to perform Satellite Laser Ranging (SLR). This facility works with other SLR telescopes around the world. Credit: NASA

NASA’s Goddard Geophysical and Astronomical Observatory in Greenbelt, Maryland, routinely bounces lasers off satellites, to perform Satellite Laser Ranging (SLR). This facility works with other SLR telescopes around the world. Credit: NASA

Japanese and Taiwanese researchers have used old satellite technology to add a decade onto modern gravity-based measurements of Greenland’s ice loss. They used measurements gained by tracking satellites with lasers, getting ‘rough data’ compared to more modern technology, but still confirming an acceleration already seen between the 1990s and 2000s. “There was no mass loss in the 1990s, but there was an acceleration after the year 2000,” says Kosuke Heki from Hokkaido University in Japan.

Though we don’t notice it, Earth’s gravity changes slightly across its surface, because mass isn’t shared equally over it. The link Isaac Newton famously discovered between mass and gravity means that where there’s more mass – for example, where ice sheets sit – gravity is stronger. Since their launch in 2002, twin satellites called Tom and Jerry have been chasing each other around the planet in a game of orbital cat-and-mouse to track these changes. They bounce microwaves from one to the other that scientists can use, among other methods, to track hair’s-breadth changes in the distance between them caused by changes in gravity.

Using Tom and Jerry, also known as the GRACE experiment, scientists have already shown the severity of global warming’s impact on Greenland. They found evidence that Greenland’s ice mass loss is now five times faster than it was in 1992. But for the data from the 1990s there were no gravity measurements. Instead, the researchers worked out the ice mass using laser or radar signals that had been bounced off the glaciers to record their shape, which is known as altimetry . Read the rest of this entry »

How a beer bottle helped reveal rapid past climate change

According to Willi Dansgaard "A sophisticated experimental set-up on the lawn became the beginning of a new field in geophysics." Credit: Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen.

According to Willi Dansgaard “A sophisticated experimental set-up on the lawn became the beginning of a new field in geophysics.” Credit: Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen.

On Saturday June 21, 1952, in a garden in Copenhagen, Denmark, raindrops fell through the slim neck of a beer bottle, splattering and splashing as they hit its bottom. But the bottle wasn’t carelessly left behind – Willi Dansgaard had inserted a funnel into its neck so he could use it for an experiment. He was watching it closely, collecting rain to later measure in his lab. Each drop brought Willi closer to revealing the secrets of Earth’s history, by giving scientists a way to work out temperature from ancient ice. In doing so, he would help show how climate can change much faster than experts had thought possible.

Willi was born in Copenhagen in 1922, living and studying physics and biology there until going to work for the Danish Meteorological Institute (DMI) in 1947. The DMI sent Willi and his wife Inge to Greenland, first to study the Earth’s magnetic fields, and then to help improve the reliability of weather forecasts. Their time there left the pair with ‘deep impressions of the course of Greenland nature, its forces, its bounty, its cruelty, and above all its beauty,’ Willi wrote in his autobiography. ‘We were both bitten with Greenland for life, but after a year the need for further education forced us to turn homeward.’

So in 1951, Willi took a job at the biophysics research lab at the University of Copenhagen, where his first job was to install a mass spectrometer. Able to distinguish between chemicals using weight differences, mass spectrometers are often described as atomic-level weighing scales. But they actually measure molecules’ weight by firing them through an electromagnetic field at a detector, similarly to how bulky old TVs fire electrons at their screens. Though mass spectrometers existed since the early 20th century, Second World War US efforts to produce uranium for an atomic bomb had boosted their power. Willi set up the type of machine that had been invented in the course of that work, so his department could detect tracers used in medicine and biology.

By 1952, Willi knew that his mass spectrometer could separate forms of the same chemical elements – or isotopes – that could differ in weight by as little as a single neutron. And faced with a wet weekend in June, he wondered whether the amount of these isotopes in rainwater could change from one shower to the next. ‘Now when I had an instrument that ought to be able to measure it, there was no harm in trying,’ he writes. ‘I placed an empty beer bottle with a funnel on the lawn and let it rain.’

Read the rest of this entry »

Lifting the fog of war and climate

FIDO (Fog Investigation Dispersal Operations) petrol burners are ignited on either side of the main runway at Graveley, Huntingdonshire, as an Avro Lancaster of No. 35 Squadron RAF takes off in deteriorating weather, 28 May 1945.Guy Callendar helped devise the FIDO system.

FIDO (Fog Investigation Dispersal Operations) petrol burners are ignited on either side of the main runway at Graveley, Huntingdonshire, as an Avro Lancaster of No. 35 Squadron RAF takes off in deteriorating weather, 28 May 1945. Guy Callendar helped devise the FIDO system.

  • This is part two of a two-part post. Read part one here.

In November 1943, the British Royal Air Force used a new secret weapon in anger for the first time. Called FIDO, or Fog Investigation and Dispersal Operation, it was a system of petrol burners that cleared fogbound airfields by raising their temperatures several degrees. It let the Allies launch and land warplanes safely when their enemies were still grounded by poor visibility. Newspapers billed it as near miraculous, crediting it with shortening the war and saving the lives of 10,000 airmen. But for one of the engineers behind it, Guy Callendar, it was just another way to combine his interest in weather and climate with his heat expertise.

From 1922-1941 Guy had worked on the Callendar Steam Tables, which he filled with data to help other engineers and scientists working with steam equipment. But after a decade carefully measuring the interaction between temperature, pressure and other properties in steam, his thoughts turned increasingly to climate. By 1938 he had stood up in front of a room of sceptical meteorologists, telling them that the world was warming, and burning fossil fuels was the cause. And while that marked a key turning point in identifying and understanding global warming, his later work in collecting evidence for that argument may have been still more important.

With his CO2 theory getting a frosty reception, and with his steam work winding down, Guy scoured scientific papers for evidence to back his argument. Since scientists like Svante Arrhenius had first suggested an important role for CO2 in climate in the 19th century and even earlier, physics had made some important advances. Earlier scientists knew that gases like CO2 absorbed infrared radiation but in the 1920s they made leaps forward in understanding why.

The frequency of the wave of infrared radiation, the number of oscillations it goes through per second, matches motions in the gas molecules that absorb it. For example, if the molecules spin at a similar frequency to the radiation’s oscillations, they can absorb the its energy. Also, atoms such as oxygen and carbon in the molecule can move, pushed by thermal energy and pulled by chemical bonds between them. That creates a vibration, and if the frequency of the vibration matches that of the infrared radiation, the vibration can absorb the radiation’s energy Read the rest of this entry »