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.’

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Speeding poor countries’ progress could halve farming emission growth

Improving agricultural productivity - particularly without increasing fertiliser use - could help cut greenhouse gas emissions from agriculture. Credit: IIASA

Improving agricultural productivity – particularly without increasing fertiliser use – could help cut greenhouse gas emissions from agriculture. Credit: IIASA

If the world’s poorer countries progress faster towards farming like richer ones the improved food availability could help fight climate change. That’s according to Austrian and Australian scientists who say that they have looked at climate change’s links to both animal and crop farming in the most depth yet.

Hugo Valin from the International Institute for Applied Systems Analysis (IIASA) in Laxenburg, Austria, and his colleagues studied cutting the gaps between farming output in rich and poor countries. They say halving this ‘yield gap’ for crops, and reducing it by a quarter for animals, could halve the increase in worldwide greenhouse gas emissions from farming between 2000 and 2050. But they have also found that improved farming methods could raise how much food people eat, meaning that emission reductions aren’t as much as they would be otherwise.

“The widespread idea is that intensifying crop farming is beneficial to the environment because it spares land,” Hugo told me. “We show that it is more complex than this. Intensification also stimulates consumption because it allows farmers to supply more food at affordable prices.”

Farming produces about a third of all ‘man-made’ greenhouse gas emissions, though a lot of them are actually from farm animals’ belches and farts and manure. The rest come from chemical reactions of fertiliser used on crops in soil, and also gases released from soil, plants and trees when forests are converted into farmland. Four-fifths of these emissions happen in developing countries. The world’s population is set to grow from around 7 billion people today to between 8.3 and 10.9 billion by 2050. We need more food for those extra people, which will add to the greenhouse gases farming puts into the air each year. Read the rest of this entry »

Scientists spotlight rock’s role in carbon capture success

Equipment for monitoring seismic activity being deployed in a borehole at the Weyburn CO2 storage site in Saskatchewan, Canada. Credit: University of Bristol

Equipment for monitoring seismic activity being deployed in a borehole at the Weyburn CO2 storage site in Saskatchewan, Canada. Credit: University of Bristol

Climate change is a problem that many would like to bury – and indeed ‘burying’ CO2 deep underground might be needed to get it under control. And injecting the greenhouse gas among the rocks below us on a large scale is a serious option, if the storage sites are chosen carefully. That’s according to a study of three sites where ‘carbon capture and storage’ (CCS) has been done, published by University of Bristol’s James Verdon and his teammates this week. “Too often CCS is seen as a binary thing – it’ll either be brilliant or hopeless, depending on whether you are for or against,” James told me. “This study shows that every CCS site will be different – there won’t be a one size fits all solution.”

Scientists think it will be dangerous if global temperatures go more than 2°C above the pre-industrial average from 1850-1899. That’s recognised by governments in a non-binding climate change target in the Copenhagen Accord in 2009, where many also pledged actions to cut their CO2 emissions. But we continue to pump out ever more CO2, making the chances of sticking to the target through emission cuts alone ever slimmer.

CCS, which captures CO2 where lots would otherwise be released and then stores it where it can’t reach the air, is an alternative approach. Though the cost of the technology needed to do this has meant projects have been delayed and even abandoned, eight large-scale CCS projects are operational today. James has worked at two: Weyburn in Canada, and In Salah in Algeria. At a meeting of British CCS scientists he mentioned this to Andy Chadwick from the British Geological Survey in Nottingham, who had worked at the Sleipner CCS project in Norway. They realised that comparing the sites could help answer one of the biggest potential issues around CCS beyond cost: how rocks respond to CO2 injection. Read the rest of this entry »

Extra climate targets urge faster CO2 cuts

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 »