Extra climate targets urge faster CO2 cuts

July 3, 2013 — andyextance
University of Bern's Marco Steinacher has helped show that setting limits on different aspects of damage from climate change will likely limit CO2 emissions more than just temperature alone. Credit: University of Bern

University of Bern’s Marco Steinacher has helped show that setting limits on different aspects of damage from climate change will likely limit CO2 emissions more than just temperature alone. Credit: University of Bern

To give the world a chance of restricting damage caused by climate change, we need more than just a single temperature target, Swiss researchers have found. Marco Steinacher and his teammates at the University of Bern worked out the chances that climate change can be kept within harmful limits in six different areas. “Considering multiple targets reduces the allowable carbon emissions compared to temperature targets alone, and thus CO2 emissions have to be reduced more quickly and strongly,” Marco told me.

In December 2009, world leaders agreed the non-binding Copenhagen Accord, which ‘recognises’ that scientists think world temperature increases beyond 2°C above the pre-industrial average from 1850-1899 would be dangerous. It also mentions sea level rise, protecting ecosystems and food production. And as climate talks have continued since the 1990s, specific new dangers of CO2 emissions have been found. One serious impact that has been realised in the last decade comes from the fact that oceans absorb CO2 from the air, which makes the seas more acidic. That can make it harder for sea creatures’ shells to form, and together with warmer seas can damage coral, and in turn reduce fish numbers available for food. “Traditional climate targets have not addressed this effect,” Marco said.

It might seem reasonable to assume that negotiating climate deals on temperature limits alone could protect against other dangers. But until recently only very simple ‘Earth system’ models were available to test this against the idea of having several targets. They couldn’t simulate regional effects on quantities such as ocean acidification or farming productions, Marco said. “Climate targets that aim at limiting such regional changes can only be investigated with a model that has a certain amount of complexity,” he explained. Read the rest of this entry »

Posted in Acidification, Action, agriculture, climate, environment, Global warming, Modelling, news, Oceans, Regional prediction, science, University of Bern. Tags: , , , , , , . 3 Comments »

Missed Greenland melt cause raises sea level concern

June 29, 2013 — andyextance
A team of scientists (the tiny figures in the foreground) at the southwest margin of the Greenland Ice Sheet. Almost all of the surface of the sheet melted in July 2012 - and there's a lot more ice benath the surface, that's why faster melting could be so serious for sea level rise. Credit: University of Sheffield

A team of scientists (the tiny figures in the foreground) at the southwest margin of the Greenland Ice Sheet. Almost all of the surface of the sheet melted in July 2012 – and there’s a lot more ice benath the surface, that’s why faster melting could be so serious for sea level rise. Credit: University of Sheffield

The almost complete melting of Greenland’s ice sheet surface on July 11-12 2012 was caused by climate processes not projected by models. That’s according to an international team led by Edward Hanna from the University of Sheffield, UK that has looked at what might have driven the melt. “The models used to predict future climate change are clearly deficient in simulating some of the recent jet stream changes that we have shown to be responsible for enhanced warming and ice melt over Greenland,” Edward told me. And the world needs to pay attention when Greenland defrosts, as the water it produces is a major part of sea level rise.

Having long studied the Greenland ice sheet, or GrIS, Edward was perhaps one of the people least amazed by 2012’s events. “Last year’s record melt was a bit of a surprise, but perhaps not so startling in retrospect, given strong recent warming of the ice sheet area since the early-mid 1990s,” he said. With other scientists he has also found a clear change since 2007 in early summer Arctic wind patterns relative to previous decades that has led to warm Greenland summers. In particular, jet stream patterns of winds weaving north and south in drunken circles around the pole have changed to drive warm winds over Greenland. That study also linked these changes to cool, wet summers in the UK since 2007, whose unusual wetness in 2012 is seemingly the other face of the GrIS melt coin. Read the rest of this entry »

Posted in climate, environment, Global warming, Greenland, Ice sheets, Modelling, news, Oceans, Precipitation, satellites, science. Tags: , , , , , , , , , . 3 Comments »

Worse extreme temperature effects urge farming precautions

June 20, 2013 — andyextance

Stanford University's Sharon Gourdji talks about her study on increasing extreme heat during sensitive crop flowering periods. Credit: IOP Publishing, via Creative Commons license, see citation below.

Since 1980, maize and wheat crops in many places have been increasingly exposed to extreme heat during sensitive flowering phases that can damage them and cause harvests to fail. That’s according to scientists at Stanford University, California, who predict that this problem will increase for these crops, and also hit rice. In fact, the area of maize and rice hit by such deadly heat is set to expand more quickly through to the 2050s. “Crop breeders need to think carefully about how to incorporate heat tolerance, particularly during the flowering period, into wheat, maize and rice,” Stanford’s Sharon Gourdji told me.

Our warming climate affects farming in many ways. For example higher temperatures, and the higher CO2 levels that are primarily responsible for them, can speed up the photosynthesis process that makes plants grow. Meanwhile, shifting rainfall patterns are set to have serious impacts on important farming areas. In 2011, Sharon’s teammate David Lobell and other scientists showed that overall crop production growth worldwide has been held back by such changes in the last three decades. But they didn’t discuss how environmental changes might influence future food availability.

“The net impact of all these factors is the golden question, but notoriously difficult to model,” Sharon explained. “Also, the most relevant of these factors, and the associated adaptation measures, differ by location and crop. Therefore most modelling studies to date look at net impacts on just a given region, or type of cropping system.” To make worldwide predictions that could help secure our future food supply, Sharon’s team had to concentrate on a smaller, simpler issue. “We focused on extreme heat during flowering,” Sharon said. “This is one aspect of global environmental change that could be particularly risky for crops regardless of other more gradual changes that are taking place simultaneously.”

Read the rest of this entry »

Posted in adaptation, agriculture, climate, Drought, environment, Flowering, Global warming, Modelling, news, Precipitation, science, temperature records. Tags: , , , , , , , . 4 Comments »

Deciphering climate messages via the heart of the atom

June 15, 2013 — andyextance
Vemork Hydroelectric Plant at Rjukan, Norway, which Hans Suess advised on heavy water production, telling Nazi Germany it couldn't make heavy water quickly enough for military use. His expertise with heavy water was part of an interest in nuclear science that led him to become a pioneer in carbon dating.

Vemork Hydroelectric Plant at Rjukan, Norway, which Hans Suess advised on heavy water production, telling Nazi Germany it couldn’t make heavy water quickly enough for military use. His expertise with heavy water was part of an interest in nuclear science that led him to become a pioneer in carbon dating.

When Hans Suess chose to study physical chemistry, he went nuclear, apparently overturning two generations of family tradition. Hans was born in 1909, just as his father Franz succeeded his grandfather Eduard as a geology professor at the University of Vienna. Hans got his PhD from the same university in 1936, but in studying heavy water he was set to aid the historic advances in nuclear science of the time. Yet a transatlantic scientific coincidence would bring him back to more environmental science, and see him help pioneer radiocarbon measurements. With that expertise, Hans showed humans were raising atmospheric CO2 levels, and revealed another surprising source of variations in climate.

The common theme to these achievements was how neutrons and protons combine in an atom’s nucleus. For example, hydrogen atoms found in conventional water have just a single proton in their nuclei. In heavy water, some of these atoms are replaced by a rarer form of hydrogen, known as deuterium, whose atoms have an extra neutron in their nuclei. That gives heavy water properties that can help nuclear reactors, which Nazi Germany notoriously hoped to exploit to make nuclear weapons.

With Hitler’s armies occupying Austria just two years after Hans finished his PhD, his expertise brought him to the attention of the Nazi regime. They called him in to advise a hydroelectric power plant in Vemork, Norway, that was making heavy water. Hans visited several times, reporting that it couldn’t make heavy water quickly enough for military use. Allied forces destroyed it in 1943 anyway, in audacious raids fictionalised in the film “Heroes of Telemark”.

Alongside working with heavy water, Hans studied why the chemical elements exist in the amounts that they do. The answer laid in how stable different numbers of protons and neutrons are when they come together in nuclei. He continued this work after the Second World War in West Germany, helping develop the “Nuclear Shell Theory” explanation, which other scientists won the Nobel Prize for Physics for in 1963. Suess missed out on this acclaim partly because two teams came up with the explanation at the same time. But when the other team, based at the University of Chicago, invited him to visit, Hans’ life changed course towards unravelling the secrets of Earth’s history. Read the rest of this entry »

Posted in climate, environment, Global warming, history, Ice sheets, news, Oceans, science, solar activity, Tree rings, Trees. Tags: , , , , , , , . 22 Comments »

Historical sea voyage sends manmade warming signal

June 8, 2013 — andyextance
The HMS Challenger sailed 69,000 miles, taking around 360 temperature soundings on the first global marine expedition from 1873-1876. This painting, by William Frederick Mitchell, is from its earlier life as a warship, in 1858.

The HMS Challenger sailed 69,000 miles, taking around 360 temperature soundings on the first global marine expedition from 1873-1876. This painting, by William Frederick Mitchell, is from its earlier life as a warship, in 1858.

Data from a 19th century scientific mission, the first global marine research expedition, have provided strong evidence that humans have influenced climate throughout the entire 20th century. From 1873–1876 the HMS Challenger, a corvette of the British Royal Navy, sailed 69,000 miles and took hundreds of ocean temperature soundings. Last year, scientists used its measurements to show the top 700 metres of the ocean has warmed around 0.33°C since Challenger’s voyage. Understandably, seeing a global effect in the limited Challenger data is fraught with difficulty. Nevertheless, Will Hobbs from the University of Tasmania, Australia, and Joshua Willis at NASA’s Jet Propulsion Laboratory in Pasadena, California, have now checked if this warming is linked to humans. “Even accounting for all uncertainties and limitations, the temperature change could not be realistically explained by natural variability alone, implying a long-term human signal,” Will told me.

Having swapped cannons for labs, among HMS Challenger’s projects was a series of around 360 soundings for temperature. At each sounding, its scientists dropped pressure-protected thermometers into the ocean attached to a rope every 100 fathoms (182 m) down to 1000 fathoms depth. “The scientists kept detailed records of how each measurement was taken, problems encountered, and how accurate and precise their measurements were,” Will said. “All instruments were calibrated in a lab before and after the expedition. So we have a lot of information about what level of accuracy we can expect, in some ways more than from modern automated observing systems, which are usually left to their own devices after deployment.” Read the rest of this entry »

Posted in climate, environment, Glaciers, Global warming, history, Ice sheets, Modelling, news, Oceans, science, temperature records. Tags: , , , , , , . 1 Comment »

Lifting the fog of war and climate

June 1, 2013 — andyextance
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 »

Posted in Arctic, climate, environment, Glaciers, Global warming, history, news, science. Tags: , , , , , . 17 Comments »

The well-qualified amateur who threw the spotlight back on CO2

May 25, 2013 — andyextance
Guy Callendar in 1934, about the time he turned his attention to the CO2-climate question

Guy Callendar in 1934, about the time he turned his attention to the CO2-climate question

In April 1938, a brave outsider stood up and showed a room full of sceptical experts evidence that would drive a revolution in climate science. Guy Callendar had pulled together temperature data from many parts of the world that clearly revealed global warming for the first time. Though few in the audience believed that humans could influence a planet-spanning system like climate, that’s just what Guy told them we were doing, by producing CO2.

But when better-known audience members at the Royal Meteorological Society meeting in London challenged his results, Guy fought back with a lifetime of scientific experience. He had followed in the footsteps of his father, physicist Hugh Callendar, making science the ‘family business’. But in 1938 the major part of that business so far for Guy – fully exploring the properties of steam – was nearing an end. And though climate science remained largely a hobby for him, Guy’s contributions are fundamental to our understanding of the global warming that is still ongoing today.

Guy was born in Montreal, Canada, in 1898 when his father, a pioneer in X-ray and steam physics, was a professor at McGill University. Hugh, his wife, and their three children returned to their native UK before Guy was one, when Hugh took up a position at University College, London. He then moved on to Imperial College London, where he chaired the physics department from 1908-1929. Beyond X-rays and steam, Hugh invented equipment to accurately measure and record air temperatures, wind speeds, and the Sun’s radiation. Perhaps it was these tools that inspired Guy to collect weather data, which he called his ‘figs.’, through much of his life. He took measurements so accurate that at one point they were used to form the official temperature records for central England.

In 1905, Hugh’s professorial salary and inventions bought a four story, 22-room house in Ealing. Life wasn’t entirely idyllic however, as by then Guy had been accidentally blinded in one eye with a pin by his brother Leslie. Further danger followed partly from Hugh’s encouragement of his children’s interest in science. He converted a greenhouse in Ealing into a laboratory, only for Leslie to destroy it while trying to make TNT. With his partial blindness preventing him from fighting in the First World War, Guy left school in 1915 to join his father’s laboratory. He performed X-ray tests, such as looking for cracks and other faults in aircraft engines, introducing him to the science of energy carried in waves. Read the rest of this entry »

Posted in climate, environment, Global warming, history, news, science, temperature records. Tags: , , , , , , . 17 Comments »

Ocean heat puts pressure on poorest fisheries

May 18, 2013 — andyextance
Warm water Red Mullet catches in the UK have increased as sea temperatures have warmed, which William Cheung has linked to global warming. Credit: Nate Gray: A Culinary (Photo) Journal via Flickr Creative Commons License

Warm water Red Mullet catches in the UK have increased as sea temperatures have warmed, which William Cheung has linked to global warming. Credit: Nate Gray: A Culinary (Photo) Journal via Flickr Creative Commons License

Since 1970, our warming seas have driven fish across the world into cooler, deeper waters, potentially threatening fishing in Earth’s hottest seas. By analysing worldwide fish catches, Canadian and Australian scientists have found that the proportion of warmer-water fish caught has steadily grown. And in future, the warmest waters are set to become too hot for some of the fish that might previously have been caught there.

“Tropical fisheries are likely to be most impacted by ocean warming,” William Cheung from the University of British Columbia in Vancouver, Canada, told me. “We expect that the current trend would continue, and will reduce the catch for tropical fisheries. Many tropical fishing communities are in developing countries with limited socio-economic scope to deal with changes in resource abundance. Thus, these communities are most vulnerable to ocean warming.”

Like all living creatures, fish have a range of temperatures that they can comfortably live in. Sea temperatures are rising, with the US coast from North Carolina to Maine reaching the warmest level in 150 years last year, for example. Changing climate has already been linked to fish catches in some places, with William previously suggesting it’s behind rapid increases in warm-water red mullet catches around the UK. “However, there was no study that assessed the linkages between ocean warming and fisheries changes in the global scale,” he said.

So William and his teammates set about bringing together fish catch information from 52 ecosystems, including most of the world’s fisheries. That included data on 990 species, which the scientists analysed using a new measure, the ‘mean temperature of the catch’ or MTC, which William also calls a ‘fish thermometer’. To find the MTC, the scientists start by working out the preferred temperature of each species, based on the sea water temperatures in the areas that they used to live in. “For example, fishes that live in colder area, such as cod, will have a lower preferred temperature than a tropical fish, such as a tropical grouper,” William explained. Read the rest of this entry »

Posted in climate, environment, Fish, Global warming, Mitigation, Modelling, news, Oceans, science. Tags: , , , , , , . 2 Comments »

Arctic mission recovers record of surprising warmth

May 9, 2013 — andyextance
All cargo for the drilling operation on Lake El'gygytgyn in winter 2008/09 had to be transported to the lake from the nearest settlement, Pevek, located 360 km north across the frozen tundra with trucks supported by bulldozers. Credit: Pavel Minyuk

All cargo for the drilling operation on Lake El’gygytgyn in winter 2008/09 had to be transported to the lake from the nearest settlement, Pevek, located 360 km north across the frozen tundra with trucks supported by bulldozers. Credit: Pavel Minyuk

A warm climate with CO2 levels similar to today delayed ice sheets from forming over land in the Arctic until less than 2 million years ago. That’s the latest instalment in a climate history scientists are building using sediment from a lake created by a giant meteorite impact around 3.6 million years ago. The international team has found that 3-3.2 million years ago, summer temperatures in the region were about 8°C warmer than they are today.

Julie Brigham-Grette from the University of Massachusetts, Amherst, explained that other scientists have estimated CO2 levels in the Pliocene period from 5.3 to 2.6 million years ago. “Though the estimates are quite broad, most scientists suggest that 2-3 million years ago CO2 levels may have been similar to today,” she told me. “Our data are consistent with that – the world today could be headed toward a Pliocene-like world.” And as well as pointing to the warmer future, these findings could also help unpick climate puzzles from our past.

These insights are the prize Julie and her team-mates sought on an epic trek to North-East Russia’s frozen wilderness in 2009. She was chief scientist for the US side of the team, leading the expedition alongside Martin Melles and Pavel Minyuk, chief scientists for the German and Russian sides. Their goal lay at the bottom of Lake El’gygytgyn, or Lake E. A 13 km wide crater blasted by a meteorite up to a kilometre in diameter that filled with water, Lake E has slowly collected sediment ever since. It’s unusual because it largely escaped damage from the creep of ice sheets, meaning scientists can use its sediment to rebuild conditions further back in time.

And to get there, Julie, Martin and Pavel had to pave political, financial, logistical, and actual physical paths, Julie explained. “This lake sits in an area that has no roads,” she said. “It was an amazing logistical feat to gather the drillers and equipment and get there, without damaging the environment. It was the most difficult scientific project I’ve ever undertaken.” Read the rest of this entry »

Posted in Arctic, climate, environment, Glaciers, Global warming, history, Ice sheets, news, Oceans, science, sea ice, temperature records. Tags: , , , , , , , . 1 Comment »

Google search basis undermines sunspot-winter coldness link

May 4, 2013 — andyextance
Franck Sirocko's 2012 study incorrectly dated this 1929 postcard identifying a year that the Rhine froze as being from 1963, which is one of many problems Geert Jan van Oldenborgh and his colleagues found with it. Image from van Oldenborgh et al, used under Creative Commons license, see citation below.

Franck Sirocko’s 2012 study incorrectly dated this 1929 postcard identifying a year that the Rhine froze as being from 1963, which is one of many problems Geert Jan van Oldenborgh and his colleagues found with it. Image from van Oldenborgh et al, used under Creative Commons license, see citation below.

European researchers have strongly criticised a recent study linking cold winters in the continent to cycles affecting the sun for relying on a shallow internet search. In August 2012, Franck Sirocko at University of Mainz, Germany, and his teammates linked cold years to sunspot activity lows using historical reports of when the river Rhine froze. But their results disagree with previous research, and previously unpublished findings from Geert Jan van Oldenborgh from KNMI, the Royal Netherlands Meteorological Institute, in De Bilt. And when Geert Jan looked into why this was, he found problems common in research on this topic over 50 years ago, updated for the internet age.

“These problems are fundamental – all the results that they claimed are spurious,” Geert Jan told me. “It is simply an incorrect paper. Usually incorrect results are just ignored, they do not get cited much and are quickly forgotten. However, this time we took the unusual step to write a comment on the paper. This decision was based on the low quality and the wide publicity it was given.”

That publicity came largely because the American Geophysical Union, which published the 2012 paper, put out a press release about it that the media reported widely. It tells how Franck’s team used historical documents to find that the Rhine froze in multiple places fourteen different times between 1780 and 1963. 10 of the 14 freeze years occurred close to the point in an 11 year cycle when there are fewest sunspots. “We provide, for the first time, statistically robust evidence that the succession of cold winters during the last 230 years in Central Europe has a common cause,” Franck said in the press release.

Sunspot cycles had been linked to weather throughout the 19th and 20th centuries, until Barrie Pittock started going over the evidence in the 1970s. Barrie, who led the Climate Impact Group at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia until his retirement in 1999, found no link beyond day-to-day weather effects. He also found many studies had used bad or incomplete data to say otherwise. Read the rest of this entry »

Posted in climate, environment, Global warming, IPCC, news, Scepticism, science, solar activity, temperature records. Tags: , , , , , . 5 Comments »
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