Welcome to Simple Climate! The site designed to provide you with straightforward explanations about climate change, letting you read, react and then get on with your life.
I was invited to speak to a group of teenagers on climate strike in Oxford recently. Like many scientists, I support the strikes, but also find them disturbing. Which I’m sure is the idea.
Today’s teenagers are absolutely right to be up in arms about climate change, and right that they need powerful images to grab people’s attention. Yet some of the slogans being bandied around are genuinely frightening: a colleague recently told me of her 11-year-old coming home in tears after being told that, because of climate change, human civilisation might not survive for her to have children.
The problem is, as soon as scientists speak out against environmental slogans, our words are seized upon by a dwindling band of the usual suspects to dismiss the entire issue. So if I were addressing teenagers on strike, or young people involved in Extinction Rebellion and other groups, or indeed anyone who genuinely wants to understand what is going on, here’s what I’d say. Read the rest of this entry »
All gas and bulls**t. That’s me – or so some of my critics think. And this time they’re right, although not in the way they think they are.
Over recent months I’ve been delighted to work with the enormously talented Adam Levy, better known as ClimateAdam, on a couple of videos. They deal with just why greenhouse gases trap energy in the atmosphere, a subject that has come up when I’m discussing climate with friends. It’s hard to understand how gases that are present in the atmosphere in such tiny amounts compared to oxygen and nitrogen can be so powerful. But it’s all to do with molecules absorbing light energy in a way that makes their atoms vibrate, which is also how substances get their colours.
I know this because it came up in my first year undergraduate chemistry course at the University of Southampton. My amazing lecturer, Martin Grossel, demonstrated the principles by standing on a stool with balloons in each hand, representing atoms. He then wiggled his arms to represent the vibrations in question. This is the kind of thing that just doesn’t come across in writing. So when I bumped into Adam at the Association of British Science Writers’ annual award ceremony last year, I suggested he put something like this into some of his videos. He then used the opportunity to apply for some science communication funding from the Royal Society of Chemistry. Having secured that cash, through the course of 2018 we’ve been working together on the script, and here are the final products:
These videos also show why carbon emissions are not the same as carbon dioxide emissions – the difference is two oxygen atoms – a common confusion that jangles my chemical sensibility. Apologies in advance if I ever annoyingly pull you up on this.
But the bulls**t is what excites me the most. As our second video above shows, methane is a potent greenhouse gas and its emissions from farming – including from cows belching and pooing – are hard to reduce. So one of the companies I wrote about is looking to store the manure, collect the methane and cryogenically store it. Then, farmers can burn it when energy is needed and feed electricity into the grid, displacing natural gas, for example. But like the other gases, the liquid methane is portable and could be used to run trucks that currently use diesel, and eliminate the horrible pollution that brings. Or it could be used to supply the many people in rural areas that – surprisingly to many urbanites – have no access to the gas grid.
It’s been months and months since I last posted here, but I hope that some of you have been following my climate writings elsewhere. I’ve used the time I used to put into blogging for lots of other things, including becoming a director of Exeter Community Energy this year, supporting renewable electricity generation and energy efficiency.
In case you hadn’t noticed, the climate issue is more pressing than ever. I’ve valued how Simple Climate enabled me to see how true that is. But having learned more about science writing, I appreciate that those reading this are mostly going to be those who likewise care about the climate. You guys know this stuff is important already – and so I’ve mainly decided it’s time to stop faffing around with blog posts and go do something practical. If you feel the same way, seeking out your local community renewable energy group is one excellent way to make a difference.
Why do ostriches stick their heads under the sand when they’re scared?
They don’t. So why do people say they do? A Roman named Pliny the Elder might be partially to blame. He wrote that ostriches “imagine, when they have thrust their head and neck into a bush, that the whole of their body is concealed.”
That would be silly—birds aren’t that dumb. But people will actually pay to avoid learning unpleasant facts. It seems irrational to avoid information that could be useful. But people do it. It’s called information aversion.
Here’s a new experiment on information aversion:
In order to gauge how information aversion affects health care, one group of researchers decided to look at how college students react to being tested for a sexually transmitted disease.
That’s a subject a lot of students worry about, according to Josh Tasoff, an economist at Claremont Graduate University who…
Uncertainty cuts both ways highlights University of Bristol’s Stephan Lewandowsky – if your preferred estimate is at the low end of a range, you’re neglecting similarly likely high end estimates. Image credit: University of Bristol
These messages could hardly be any clearer, but still some of us remain uncertain on the need to act. The best argument for waiting until we’re more certain to act is that if climate change turns out to be harmless, our efforts to fight it will be wasted. Even simple things like current weather are enough to sway our opinions, and when uncertain it’s always tempting to feel like we don’t need to do anything. But that’s the wrong reaction to uncertainty on climate change, according to psychologist Stephan Lewandowsky from the University of Bristol, UK.
The researchers have found that greater uncertainty over how much Earth warms in response to our CO2 emissions would actually raise forecasts of average damage costs from climate change. Greater uncertainty also means projections see it as more likely that steps to cut emissions won’t keep the world below warming levels governments have agreed we must avoid. So, if we are unsure whether we can slow the climate juggernaut down before we smash into the wall, we’re better off hitting the brakes earlier. As Stephan explained, ‘uncertainty is no one’s friend’.
Evidence is piling up against the economic argument for waiting to see if climate sensitivity is less than 1°C per doubling of CO2. Image copyright Springer, see reference below.
The 2010 blizzards in the northeastern US they called the ‘Snowpocalypse’ buried this Maryland street, drove senators to deride the idea of global warming, and Columbia University researchers to look at how temperature influences our outlook on climate change. Image credit: BKL, used via Flickr Creative Commons license.
That baking hearing likely played on how we think in a way psychologists had just started to untangle in the previous decade. That is, how we judge things is often dominated by a simple sense of our personal experience, rather than a deeper analysis of evidence available to us. “Numerical judgments are hard, so we grasp at whatever more tangible we can find,” Elke Weber, from Columbia University in New York, explained.
Identifying this tendency to answer an easier question, known as substitution, helped psychologist Daniel Kahneman win a Nobel Prize for Economics. And when it comes to our opinion on climate change, recent temperatures are especially important, Elke and her colleagues have shown over the last three years.
In 2010, a rather different extreme in the US capital drew Elke’s husband Eric Johnson to study this effect. Then, two massive snowstorms struck in one week in February, an event that was dubbed the ‘Snowpocalypse’, leading senators to deride the possibility of climate change. His team therefore looked at whether local weather information gets falsely substituted for global climate in three studies in the US and Australia.
A measurement taken on a shaded back deck in Oswego, Oregon on July 29, 2009 at 6pm. 41.3°C or 106.34°F – just one example of increasingly common hot summers in the Northern Hemisphere. Image copyright Sean Dreilinger used via Flickr Creative Commons licence.
Human influence on climate is set to make otherwise unusually hot summers in the Northern Hemisphere more frequent, even if the current warming slowdown continues. That finding, from a new study by Youichi Kamae from the National Institute for Environmental Studies in Tsukuba, Japan, and his colleagues, could now heat up climate talks. “The recent hot summers over land regions and the climate hiatus have opposite effects on ongoing global negotiations for climate policies,” Youichi underlined. “The findings of this study can have significant implications for policy makers.”
Over the past 15 years, growing ‘anthropogenic’ or human-emitted CO2 hasn’t turned into significant average temperature rises on the Earth’s surface. The top levels of the oceans haven’t warmed significantly either, even though heat is still building up deeper down. However in that time sometimes deadly hot summers have become more common in Earth’s northern half. It’s not clear how that’s happening without average temperatures increasing faster. One possible part of the explanation could be a fast response to greenhouse gas emissions that Youichi and other scientists had previously found. “The fast response over can largely be interpreted as direct land surface warming due to CO2,” Youichi told me.
The Japanese team’s search for a better explanation had a big question at the centre: How much of this climate change is natural, and how much is man-made? Not able to easily experiment on the planet to investigate, they did what climate scientists usually do for such ‘attribution studies’, and turned to computer models. Simulating the world with and without human greenhouse gas emissions and comparing the results, scientists are increasingly trying to pinpoint whether climate change directly caused particular extreme weather events. They’re trying to build up lots of evidence about a single event to be sure that their result isn’t random, and that takes lots of computer time and power. Read the rest of this entry »
The odds that yields of maize will fall by a tenth over the next 20 years have shortened from 1-in-200 to 1-in-10. Image copyright Raman Sharma, used via Flickr Creative Commons license.
With the next two decades set to see a stronger increase in demand for food than the rest of the 21st century, declining harvests would cause some serious problems. Right now crop yields are growing, but could climate trends cause them to fall by a tenth, say, over the next 10-20 years?
That’s the question David Lobell from Stanford University in California and Claudia Tebaldi from the US National Center for Atmospheric Research in Boulder, Colorado have tried to answer. They find that if the world wasn’t warming, the chance of yields decreasing by a tenth over the next 20 years would be less than 1-in-200. However, climate change has made shrinking yields more likely, shortening the odds to a 1-in-10 chance for maize and a 1-in-20 chance for wheat.
“It was surprising to see how likely it is nowadays for climate trends to significantly cut into yield progress,” David told me. “It is still more likely than not that climate will be a slight drag on progress instead of a major factor. But we can’t rule out a major slowdown, and that means we should probably think through that type of scenario to figure out how to prepare for it.”
Such near-future climate forecasts are unusual, David underlined. “Longer periods allow the signal of climate change to become clearer compared to natural variability,” he explained. “But it may simply be that most of the initial questions about climate change were about the long timescales, to decide about questions related to energy choices and emissions. Now, a lot of questions are related about how to properly adapt to the changes happening now.”
What will happen to crops is central to David’s interests as associate director of Stanford’s Center on Food Security and the Environment. “I often get asked by governments or the private sector if climate change will threaten food supply in the next couple of decades, as if it’s a simple yes or no answer,” the scientist revealed. “This was especially true of a committee I recently served on focused on social stresses from climate change in the near-term. The truth is that over a 10 or 20 year period, it depends largely on how fast things warm, and we can’t predict that very precisely. So the best we can do is put odds on things.” Read the rest of this entry »
UK Prime Minister David Cameron visiting Dawlish a week after the storms that demolished the sea wall that supported the train line. Image copyright Number 10, used via Flickr Creative Commons license.
Taking the train along the Devon, UK, coast earlier this week I was hypnotised by the lapping waves I saw through the window, and their concealed power. On such a sunny day, the rail journey through Dawlish is perhaps the most beautiful I’ve been on. But in February its ocean-hugging route became its downfall, when storms demolished the sea wall it rests on. Now, thanks to 300 fluorescent-jacket clad workers who performed £35 million worth of repairs, the dangling tracks I saw on TV news are a fading memory. It’s an impressive achievement, but could we afford it if – due to climate change, for example – such ‘orange armies’ had to do battle more often?
The significance of that question was emphasised by Chris Field from Stanford University in California, when I saw him talk recently. Highlighting that all parts of the world are vulnerable to climate change, Chris showed the below image of New York City in 2011, during Hurricane Sandy. “The existing climate created a situation that caused over $50 billion in economic damage for a region of the world that had a vast amount of economic resources and had a response plan in place,” he underlined. “It just wasn’t a plan that was up to the challenges that they faced.” If climate change causes more $50 billion-damage events, can we afford that?
If New York can be taken unaware by Hurricane Sandy, what happens elsewhere, when sea level’s higher? Image credit: Chris Field/IPCC
Just before the ocean crippled the south-west UK’s rail services, Jochen Hinkel from the Global Climate Forum in Berlin, Germany, and his team were answering a similar question. In a paper published in the Proceedings of the National Academy of Sciences of the USA in February, Jochen looked at coastal flood damages from projected sea level rise. When I therefore asked him about his work, he was quick to put climate change-driven sea level rise’s role in Hurricane Sandy and this year’s UK storms into context. Read the rest of this entry »
After 10,500 years of farming them, does climate change mean we humans must limit our reliance on cows, or just change how we treat them? Image copyright fishhawk, used via Flickr Creative Commons licence.
Whenever I come across cows here in the southwest of the UK, usually placidly munching on a mouthful of grass, they always seem too lovable to be villains. But as we face growing twin challenges of feeding the world and fighting climate change, they’re increasingly getting a bad reputation.
Some scientists highlight reducing how much beef we eat, in particular, as an important step towards future sustainability. They say only about three or four parts in 100 of the energy in livestock feed becomes our food, while the rest is lost as manure, heat, digestive gases and slaughter by-products. Switching to more intensively farmed chicken or pork and plant-based food would be more efficient, the argument goes. It also gives a greater chance to trap carbon from waste material, which might otherwise become planet-warming greenhouse gases, as biochar that can help improve soil fertility.
We can’t ignore what that promises for feeding the world in the future, but we can’t ignore cows’ greenhouse gas emissions either. However, rather than beef cattle, the new paper’s authors focussed on reducing levels of the potent greenhouse gas methane coming out of the digestive systems of dairy cattle. Joanne Knapp, a consultant who has researched nutrition in ruminant animals like cattle, told me her team’s interest comes in part thanks to its backers: Innovation Center for US Dairy.
A Roman altar with the Sun in its chariot on the left, and Vulcan, the god of fire and volcanoes on the right. The climate gods long favoured the Roman Empire, with Earth’s orbital dance credited for increasing the amount of solar energy falling on Earth at the time. Image copyright: Nick Thompson, used via Flickr Creative Commons License.
Our climate has changed before. It’s something most of us realise and can agree on and, according to Skeptical Science, it’s currently the most used argument against human-caused warming. If such changes have happened naturally before, the argument goes, then surely today’s warming must also be natural. It’s an appealing idea, with an instinctively ‘right’ feel. Nature is so huge compared to us puny humans, how can we alter its course? The warming we’re measuring today must just be a natural fluctuation.
It’s such an appealing argument that at the beginning of the 20th century that’s just what many scientists thought – that humans couldn’t alter Earth’s climate. In the time since, our knowledge has come a long way. We’ve explored space, become able to build the electronics that are letting you read this, and climate science has likewise advanced and benefited from these advances.
So what do we know today that might convince the sceptical scientists of 115 years ago that we’re warming the planet? Recently, Richard Mallett, one of my Twitter friends who describes himself as sceptical about mainstream climate science, made a point that serves as an excellent test of our current knowledge:
@andyextance Climate science should be able to explain the Holocene, Roman, Medieval and current warmings and the cold periods in between.
Of the historical warmings he’s referring to, perhaps the least familiar is the Holocene, which is ironic, as the Holocene is now. It’s the current period of geological time that started at the end of the last ice age, 11,700 years ago. By 1900 scientists would have known the term, but they couldn’t explain why it wasn’t as icey as before.
Three variables of the Earth’s orbit—eccentricity, obliquity, and precession—affect global climate. Changes in eccentricity (the amount the orbit diverges from a perfect circle) vary the distance of Earth from the Sun. Changes in obliquity (tilt of Earth’s axis) vary the strength of the seasons. Precession (wobble in Earth’s axis) varies the timing of the seasons. For more complete descriptions, read Milutin Milankovitch: Orbital Variations. Image credit: NASA/Robert Simmon.
The explanation we have today comes thanks to the calculations Milutin Milanković worked out by hand between 1909 and 1941. Milutin showed that thanks to the gravitational pull of the Moon, Jupiter and Saturn, Earth’s orbit around the Sun varies in three ways. Over a cycle of roughly 96,000 years our path varies between more circular and more oval shapes. The other two ways come because Earth’s poles are slightly tilted relative to the Sun’s axis, which is why we have seasons. The angle of that tilt shifts over a roughly 41,000 year cycle. Earth also revolves around that tilted axis, like a spinning top does when it slows down, every 23,000 years.
by Myles Allen, University of Oxford
Simple Climate 