The underprepared figurehead that led climate science from calculation to negotiation

Bert Bolin discussing weather maps in Stockholm circa 1955. Image copyright Tellus B, used via Creative Commons license, see Rodhe paper referenced below.

Bert Bolin discussing weather maps in Stockholm circa 1955. Image copyright Tellus B, used via Creative Commons license, see Rodhe paper referenced below.

In 1957, at the young age of 32 and just one year after completing his PhD, Bert Bolin officially gained a new skill: leadership. Taking over the International Meteorological Institute (IMI) in Stockholm, Sweden, after his mentor Carl-Gustaf Rossby’s sudden death must have been a huge shock. But Bert gained responsibility after responsibility over the next 40 years, ultimately becoming the first chairman of the United Nations’ Intergovernmental Panel on Climate Change (UN IPCC). And though it’s hard to beat setting up a Nobel-prize winning organisation, Bert was not just an administrator – his research helped build the foundations of climate science too.

Growing up in Nyköping, south of Stockholm, Bert recorded the weather with encouragement from a schoolteacher father who had studied meteorology at university. After the pair met the Swedish Meteorological and Hydrological Institute’s deputy director when Bert was 17, he moved north to study maths, physics and meteorology at the University of Uppsala. Immediately after graduating in 1946 he went to Stockholm to do military service, where he first saw Carl-Gustaf giving a series of lectures.

By that time Carl-Gustaf had been living in the US for 21 years, pioneering mathematical and physical analysis of the atmosphere, becoming the country’s foremost meteorologist. He had set up meteorology departments at Massachusetts Institute of Technology in the 1930s, and the University of Chicago, Illinois, in the 1940s. He had also modernised the US Weather bureau and by 1946 wanted to help improve meteorology’s status in his native Sweden. As Carl-Gustaf’s renowned organisational prowess gradually pulled together the IMI, Bert came to study with him, gaining his Master’s degree in 1950.

Carl-Gustaf was collaborating with leading scientists of his time, and through some of these links Bert spent a year working in the US after his Master’s. Perhaps the most notable such relationship was with John von Neumann at Princeton University in New Jersey, who had helped develop the hydrogen bomb. John and his team had made history using arguably the world’s first computer, ENIAC, to predict weather mathematically. But when errors emerged, Carl-Gustaf asked Bert to help analyse why, using his understanding of the atmosphere to prevent such forecasts being ‘mathematical fantasy’. Read the rest of this entry »

Enhanced fingerprinting strengthens evidence for human warming role

Microwave sounding units, like the AMSU units on the Aqua satellite, shown here, can be used to take temperature measurements from different layers in the atmosphere. Ben Santer and his colleagues use this information to find a 'fingerprint' of human impact on recent climate changes. Credit: NASA

Microwave sounding units, like the AMSU units on the Aqua satellite, shown here, can be used to take temperature measurements from different layers in the atmosphere. Ben Santer and his colleagues use this information to find a ‘fingerprint’ of human impact on recent climate changes. Credit: NASA

We have left a clear climate change ‘fingerprint’ in the atmosphere, through CO2 emissions that have made air near the Earth’s surface warmer and caused cooling higher up. That’s according to Ben Santer from Lawrence Livermore National Laboratory (LLNL) in California, who started studying this fingerprint in the mid-1990s, and his expert team. They have strengthened the case by comparing satellite-recorded temperature data against the latest climate models including natural variations within Earth’s climate system, and from the sun and volcanic eruptions. Ben hopes that in the process their results will finally answer ill-tempered criticism his earlier work attracted, and lingering doubts over what causes global warming.

“There are folks out there even today that posit that the entire observed surface warming since 1950 is due to a slight uptick in the Sun’s energy output,” Ben told me. “That’s a testable hypothesis.  In this paper we look at whether changes in the sun plausibly explain the observed changes that we’ve monitored from space since 1979. The very clear answer is that they cannot. Natural influences alone, the sun, volcanoes, internal variability, either individually or in combination, cannot explain this very distinctive pattern of warming.”

That pattern emerged when scientists in the 1960s did some of the first computer modelling experiments looking at what would happen on an Earth with higher CO2 levels in the air. “They got back this very curious warming in the lower atmosphere and cooling of the upper levels of the atmosphere,” Ben explained. The effect happens because most of the gas molecules in the atmosphere, including CO2, sit relatively near to Earth’s surface. CO2′s greenhouse effect lets heat energy from the Sun reach the Earth, but interrupts some of it getting back to the upper atmosphere and outer space. Adding more CO2 by burning fossil fuels therefore warms the lower atmosphere, or troposphere, and cools the stratosphere, 6-30 miles above the Earth’s surface.  Read the rest of this entry »

What Dave Keeling did ahead of his curve

Dave Keeling in front of the pier at Scripps Institution of Oceanography in San Diego, which houses a variety of measuring equipment. Credit: Scripps Institution of Oceanography

Dave Keeling in front of the pier at Scripps Institution of Oceanography in San Diego, which houses a variety of measuring equipment. Credit: Scripps Institution of Oceanography

On 18 May 1955, Charles David Keeling – Dave to most – set up camp near a footbridge over a river in Big Sur State Park in California. Armed with a set of five litre flasks containing nothing but vacuum, he planned to suck up air samples regularly over the 24 hours. At the time it may have seemed the latest uncertain step of a young man unsure how best to combine his interest in science and love of the outdoors. But instead it became the start of a lifelong quest to accurately measure the main gas that man is changing the world’s climate with: CO2.

“At the age of 27, the prospect of spending more time at Big Sur State Park to take suites of air and water samples instead of just a few didn’t seem objectionable, even if I had to get out of a sleeping bag several times in the night,” Dave wrote in his autobiography. “I did not anticipate that the procedures established in this first experiment would be the basis for much of the research that I would pursue over the next forty-odd years.”

Growing up in the midwest US near Chicago, Dave’s interest in science was kindled at age five, when his economist father introduced him to the wonders of astronomy. To show Dave how the seasons came about, together in their living room they circled a globe around a lamp, serving as the sun. Going through school during the Second World War, Dave took a special class in preflight aeronautics as well as the conventional sciences.

He then enrolled in the University of Illinois early, during the summer, to fit in a year of study before he reached the conscription age of 17. With limited science options available at this time of year, he chose to major in chemistry. “I didn’t particularly like chemistry and repeatedly doubted that I had made the right choice,” he recalled. But before the year – 1945 – was out, the war was over, and so Dave could continue his course. Chemistry students were expected to study economics, but Dave felt that he’d had enough economics at home. So he opted out of chemistry, ultimately getting a general liberal arts degree.

Yet he was still offered a place to study for a chemistry PhD at nearby Northwestern University with a friend of his mother’s. He took it without applying for any others, but later realised his previous studies had left him unprepared. “Accepting so soon was probably a mistake,” he wrote. Required to take a minor subject as part of his studies, Dave chose geology. His supervisor even suggested he might like to make this his major, though Dave declined, graduating in chemistry after a gruelling five years. And while his skills were in great demand from the post-war chemical industry Dave wanted a job that would let him work outside. So he applied for geology roles at universities, managing to find one at the California Institute of Technology. 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 »

Altered pressure patterns bring Eurasia intense iciness

People enjoying the winter sun - typical of an anticyclone, or high pressure, weather system - on the frozen Landwehrkanal in Berlin-Kreuzberg, during February 2012, when Berlin set a record for extreme cold. Credit: onnola via Flickr

People enjoying the winter sun – typical of an anticyclone, or high pressure, weather system – on the frozen Landwehrkanal in Berlin-Kreuzberg, during February 2012, when Berlin set a record for extreme cold. Credit: onnola via Flickr

Extreme cold that has left Europe and Asia snowbound, shivering and asking, “What global warming?” in recent years has been driven by intensified high pressure patterns. That’s according to Xiangdong Zhang at the University of Alaska, Fairbanks, who has been studying how such cold snaps fit in with increasing average temperatures worldwide. “Extreme cold weather events can occur in a particular region and short time period in a warming global climate,” Xiangdong pointed out. “This may highly disrupt daily life, damage infrastructure, and impact ecosystems and environment.”

Xiangdong started thinking about extreme cold events because climate studies usually use monthly temperature averages, which overlook them. “This cannot reflect extreme cold temperatures occurring on a particular day because daily temperature changes are filtered out by the average,” he told me. “For example, the monthly averaged temperature in February 2012 was -4.9°C in Berlin. But the coldest daily temperature in the same month at the same location was -19.6°C. We don’t directly feel the monthly average temperature in our daily life. What we feel is day-by-day changes in temperature. But if we can understand mechanisms of daily temperature changes, we would be able to better understand why there is colder or warmer monthly average temperature.”

Outside of tropical areas weather patterns known as cyclones, which would be called low pressure on a weather forecast, and anticyclones, or high pressure, drive those daily temperature changes. Xiangdong had previously been part of a team that adapted an automated cyclone spotting method to look at each one separately. Last year, with researchers from Nanjing University of Information Science and Technology in China, he used that method to study records from across Europe and Asia between 1978-2012. They brought together sea level pressure data recorded every six hours by a global collection network, and daily minimum air temperatures recorded at 1337 meteorological stations.

Read the rest of this entry »

Climate limits room at the global dinner table

Reducing tillage used to prepare soil in farming can help reduce carbon emissions without also reducing crop yields. Credit: USDA Natural Resources Conservation Service

Reducing tillage used to prepare soil in farming can help reduce carbon emissions without also reducing crop yields. Credit: USDA Natural Resources Conservation Service

Part two of two

Another mid-winter feast has passed since I published the first part of this round-up of research linking food and global warming, its memory still pleasantly fresh in my mind. I’d hate to have to sacrifice any of it in the future. But what if I were forced to change or shrink my menu? You might not have to make these choices today, but scientists are helping farming adapt to a changing climate. They’re facing up to a big challenge: trying to reduce emissions, while maintaining food supplies.

As well as being affected by climate change, farming also produces some of the greenhouse gases that cause it – between one-tenth and one-third of the world’s emissions. Agricultural consultant Rob Carlton and his colleagues therefore looked at four different crop farming methods in March last year to see which would emit least greenhouse gas if the whole UK adopted it. The best approach was to dig up less left over plant material than conventional farming currently does, keeping more carbon trapped in the soil. This approach importantly produced the same amount of crops as conventional methods. That’s necessary, because converting pasture to arable land to make up crop shortfalls seen with other methods releases large amounts of greenhouse gas. “The need for emissions reductions should be viewed against demands on agriculture, which are increasing as the population and consumption increases and farmers diversify into industrial and fuel crops,” Rob said. Read the rest of this entry »

Australians overestimate climate change rejection

CSIRO's Zoe Leviston has run a survey that found Australians' actual opinions on climate change are very different from what they estimate other people think. Credit: CSIRO

CSIRO’s Zoe Leviston has run a survey that found Australians’ actual opinions on climate change are very different from what they estimate other people think. Credit: CSIRO

People in Australia overestimate how many of their fellow citizens don’t think climate change is happening, but still think their own opinion is the most common. That’s according to a survey run by Zoe Leviston from Australia’s national science agency, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), in Perth and her teammates. Roughly one person in 20 surveyed fell in the ‘not happening’ group, but on average people thought that one person in five did. That’s partly down to a well-known effect called ‘false consensus bias’, where we tend to think more people agree with us than really do. However, how politicians and the media in Australia discuss climate change could be making the effect stronger than usual.

“There is a mis-estimation of community sentiment,” Zoe told me. “Our perception of what others think is a dynamic process, and if we have these misperceptions, they can actually reinforce our own patterns of thinking. Other research has shown that people can be hesitant to speak out if they think their opinion is on the decline, because they think that they risk social censure. It’s important to communicate accurately what the consensus is, otherwise you can needlessly propagate this myth of widespread denial.”

As part of a major CSIRO research program, known as the Climate Adaptation Flagship, Zoe surveyed more than 5,000 Australians in both 2010 and 2011, 1,355 of whom completed both surveys. Among other questions, they were asked which of four statements best described their view. They could choose: climate change is not happening; don’t know whether it’s happening or not; it’s happening but natural fluctuations; or it’s happening and caused by humans.

But Zoe and her fellow CSIRO scientist Iain Walker wanted to look beyond this basic opinion. “In Australia the media and political debate surrounding climate change have often rested on these competing claims about what Australians support and what they think,” Zoe said. “We knew that people are very bad estimators of what others are thinking, so we decided to ask about that as well.” So straight after the first question, Zoe and Iain asked what proportion of Australians would choose each of the four answers. Read the rest of this entry »

Monsoon instability raises food questions for India

A street in Calcutta floods during monsoon season. After some decades of increasing rainfall, climate change could bring drier monsoons,  said Jacob Schewe from the Potsdam Institute for Climate Impact Research. Credit: Mark E Dyer/Flickr

A street in Calcutta floods during monsoon season. After some decades of increasing rainfall, climate change could bring drier monsoons, said Jacob Schewe from the Potsdam Institute for Climate Impact Research. Credit: Mark E Dyer/Flickr

Monsoon rains in India may fail more frequently as climate change proceeds into the 22nd century, German researchers said this week. That danger could be critical for farming in what is set to become the world’s most highly populated country by 2030, and would follow an already expected wetter period. “Previous studies showed that Indian monsoon rainfall would increase more or less linearly with global warming over the next century,” said Jacob Schewe from the Potsdam Institute for Climate Impact Research. “The monsoon can respond to climate change in a more complicated way. We’ve seen that it matters to look further into the future.”

In South Asia, summer monsoon rains fall as winds blow from the southwest Indian Ocean over the continent between June and September. They end when the wind direction reverses in September or October. What Indian monsoon rain seasons will do as the world warms is an important and difficult question that many researchers are trying to answer. Though more rainfall has been predicted, recent years haven’t matched that expectation. While factors like pollution have an effect, changes climate scientists already know a major climate pattern plays a very important part in monsoons.

“There is a coupling between the El Niño Southern Oscillation and the monsoon that’s been observed for a long time,” Jacob told me. In years when El Niño occurs, an air movement pattern called the Walker circulation pattern gets shifted eastward. That brings high pressure over India and weakens the monsoon. While some changes in El Niño are already happening, the Walker circulation is expected to weaken, but not for some time yet. That could mean scientists’ climate models don’t pick up its effects. “People have looked at monsoon changes but not many studies have looked beyond 2100,” Jacob said. “You really have to consider longer timescales – beyond 2100 – to assess the full range of consequences for the monsoon.” Read the rest of this entry »

Finding nature’s part in Arctic ice loss puts spotlight on human role

University of Reading's Jonny Day talks about his studies into what's contributed to Arctic ice loss

The area of the Arctic covered by ice is set to reach a record low this year* – and much of the ongoing decline is down to man-made global warming. That’s what recent research into the role of three potential natural causes of change in ice coverage done by Jonny Day from the University of Reading, UK, and his colleagues suggests. In a paper published online in scientific journal Environmental Research Letters last month, they studied these three existing sea and wind movement patterns in five different climate models. They found that one in particular, the Atlantic multi-decadal oscillation (AMO), could be responsible for between one-twentieth and three-tenths of the decline in sea ice since the 1970s. “Our work suggests that the AMO has contributed to getting us to this low sea ice state, but does not tell the whole story,” Jonny told Simple Climate. “It is still likely that man-made global warming is the major contributor to the dramatic decline in sea ice.”

Arctic sea ice loss has surprised researchers, as it’s faster than predicted by leading climate models gathered together by the UN Intergovernmental Panel on Climate Change (IPCC). That made Jonny and his co-workers from the Yokohama Institute for Earth Sciences and University of Tokyo in Japan want to look at why this was. In particular, they wanted to see how much might be down to hard-to-predict ‘internal’ climate patterns, rather than problems with measurements of the ice or models. “The large mismatch between climate model projections of sea ice and observations in the last IPCC report was concerning,” Jonny said “My colleagues and I thought that internal or ‘natural’ climate variability may play a role.”

The possible sources of that natural variability include the Arctic Oscillation (AO), which varies between stronger and weaker winds circulating the Arctic. The other two sources come from the ocean, where the AMO is a long-term cycle of temperature change. The final source, the Atlantic meridional overturning circulation (AMOC), is a large-scale ocean flow pattern that carries warm upper waters north and returns cold, deep water south. But a limited set of measurements available for the AMO and AMOC poses researchers a problem. “The oceanic causes of variability we discuss are not well observed, making such analysis difficult,” Jonny said. Read the rest of this entry »

Climate change brings landscapes to their last days

Like icebergs, much of the mass of Arctic ice lies under the surface, making studying its thickness important, as well as the area it covers. Thick, multiyear Arctic sea ice is disappearing, giving way to thin, young ice, according to University of Colorado at Boulder scientists. Credit: James Maslanik, University of Colorado

Like icebergs, much of the mass of Arctic ice lies under the surface, making studying its thickness important, as well as the area it covers. Thick, multiyear Arctic sea ice is disappearing, giving way to thin, young ice, according to University of Colorado at Boulder scientists. Credit: James Maslanik, University of Colorado

Nature’s beauty means different things to each of us – but undoubtedly it burns some images onto our souls. Our favourite scenery is less constant than we sometimes suppose,  changing from day to day and season to season. But the slowest changes can be the most heartbreaking, eventually robbing us of our favourite landscapes.

Some destructive changes you might consider man-made,  for example city sprawl overflowing, and some natural, such as coastal erosion. Landscape losses brought by global warming are a curious mixture of these two – humanity somehow pushing nature into a more savage mood.

In the two and a half years since I started this blog, I’ve often reported on science’s efforts to monitor how climate change is affecting landscapes in different parts of the world.  In this week’s blog entry I’ve decided to bring together pictures indicating what their work has told us – you can click on the pictures to read the original blog posts.

With the Arctic changing most rapidly as the world warms, it’s one of the most studied areas, and so its striking environment features highly. But if you look enough at your favourite landscapes, and at when its more regular changes happen, it’s likely you’ll already be able to see the signs of a slow and potentially troublesome revolution in progress.

Read the rest of this entry »

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