Climate change science anyone can play with

It’s all very well to read about climate change – but you can probably get a better understanding from actually exploring the data and underlying physics yourself. That’s been driven home by some recent comments on this blog by non-scientist readers wanting to do just this, or recommending that I do. Inspired by them, in this week’s blog entry I’m bringing together various different ways we can all do this. Don’t worry, I won’t tax any weary brain cells any more than they want to be. I’m organising the blog entry in order of increasing effort/difficulty – just bail out or take a break whenever you need to.

The volume occupied by the average yearly CO2 emitted by someone in the UK is as big as a building. Credit: Carbon Quilt

The volume occupied by the average yearly CO2 emitted by someone in the UK is as big as a building. Credit: Carbon Quilt

As a simple starter, try the Carbon Quilt tool that lets you see your CO2 emissions. If you click on this link or the image above you should first see the size of a ‘quilt’ or ‘patch’. That represents the average amount of CO2 people in your country emit, overlaid on a map. Try out the sphere and cube options, and the different options in the drop-down menu to see how big your carbon footprint really is.

Click here to see how hot the Earth's predicted to get in your lifetime, and the lifetimes of children born today. Credit: The Guardian

Click here to see how hot the Earth’s predicted to get in your lifetime, and the lifetimes of children born today. Credit: The Guardian

Another simple but powerful demonstration is the Guardian interactive guide to how warm it will get in our lifetimes pictured above.

Click here to see how unusual current CO2 levels are, and how much worse they're set to get. Credit: The Guardian

Click here to see how unusual current CO2 levels are, and how much worse they’re set to get. Credit: The Guardian

Still more powerful, I think, is this guide showing the significance of CO2 levels in the air hitting 400 parts per million last year. Read the rest of this entry »

Fossil fuel exporting countries should adopt green taxes

The danger that someone else might impose taxes that reduce fossil fuel consumption before fuel-exporting countries should motivate them to get there first. That’s according to Steven Davis from the Carnegie Institution for Science in Stanford, California, and his colleagues, who have looked at the links between international trade and CO2 emissions. Their “Supply Chain of CO2 Emissions” shows where goods, services and the fossil fuels the world burned, generating power and emitting CO2, came from and went to in 2004. They found that 10.2 billion tons of CO2, over one-third of global emissions, came from fossil fuels traded internationally. 6.4 billion tons of CO2 were used to make traded goods. “The sheer magnitude of emissions that are traded internationally show an inherent flaw of trying to design an effective national program to manage carbon,” Davis told Simple Climate.

Last year, Davis and his Carnegie institution colleague Ken Caldeira showed that in 2004 on average each US citizen consumed goods imported from other countries whose production emitted 2.5 tons of CO2. For Europeans, the figure sometimes exceeded four tons per person. This CO2 benefits people in the country the goods are consumed in, but is not counted as being emitted there. Instead only CO2 directly produced in a country is considered in international negotiations seeking to fight climate change by limiting emissions.

But as CO2 emissions are also closely tied to economic growth, developing countries – and China in particular – are fighting hard to retain the right to emit and develop themselves further. Developing/developed world conflict is a regularly feature of climate negotiations, including in the Copenhagen summit in 2009 that failed to produce a binding treaty to control CO2 emissions. Yet, many countries did make their own pledges to cut CO2 emissions. One potential tool they can use to reduce CO2 emissions is through tax, for example China’s resource tax, and Australia’s upcoming tax on its biggest emitters. Read the rest of this entry »

Saturday round-up: Cutting emissions, teacup by teacup

Heavily CO2 emitting coal-fired power stations like these are likely to supply the electricity to use to boil your kettle. And like your kettle, those power stations produce steam, which are the clouds shown here, not CO2 or smoke. Credit: Imperial College.

Heavily CO2 emitting coal-fired power stations like these are likely to supply the electricity to boil your kettle. And like your kettle, those power stations produce steam, which are the clouds shown here, not CO2 or smoke. Credit: Imperial College.

Your kettle and the milk you put in your hot drink are actually both powerful weapons with which to slash greenhouse gas emissions, research has underlined this week. For example, the energy the kettle uses could produce up to 60% more greenhouse gas emissions than governments have been assuming, claims Imperial College’s Adam Hawkes. “This means any reduction we make in our electricity use could have a bigger impact on the amount of carbon dioxide emitted by power stations than previously thought,” Hawkes explained. “However, this also acts in reverse: a small increase in the amount of electricity we use could mean a larger increase in emissions than we previously thought, so we need to make sure we do everything we can to reduce our electricity use.”

Hawkes studied emissions in the UK from 2002 to 2009, where the government estimates that CO2 emissions are 0.43 kilograms per kilowatt hour. That figure comes from averaging the amount of emissions produced by each different type of power source, a method commonly adopted across the world. However this ignores the fact that in the UK sudden changes in electricity demand are mainly met by coal-fired power stations, which produce lots of CO2. “A change in demand does not act upon all elements of the electricity system proportionally,” Hawkes wrote in a paper published in the journal Energy Policy last Tuesday. Read the rest of this entry »

Overheating lizards raise climate alarm

The cool mountain habitats where many of the Sceloporus lizards are found have been subjected to very rapid climate warming, resulting in the local extinction of many species, including Sceloporus mucronatus (pictured here: a pregnant female). These are live-bearing lizards that evolved very low body temperatures for these cool environments and this low body temperature makes them extremely susceptible to extinction from climate warming. Credit: Barry Sinervo

The cool mountain habitats where many of the Sceloporus lizards are found have been subjected to very rapid climate warming, resulting in the local extinction of many species, including Sceloporus mucronatus (pictured here: a pregnant female). These are live-bearing lizards that evolved very low body temperatures for these cool environments and this low body temperature makes them extremely susceptible to extinction from climate warming. Credit: Barry Sinervo

Climate change is wiping out whole communities of lizards across the world and other animals are likely to follow suit, and may already be suffering. That’s according to Barry Sinervo of the University of California, Santa Cruz, who has studied lizard populations as part of an international scientific team. “Averaged across the planet, life has become intolerably hot for 5% of the world’s populations of lizards since 1975,” Sinervo told Simple Climate. “This has pushed these populations to extinction. The global level of lizard extinctions is very scary.”

Sinervo explains that all animals have developed temperature limits as a result of millions of years of evolution. Temperatures are currently changing too fast for animals to evolve and adapt to them. “All animals are susceptible,” he explained. “It is just easier for us to prove these thermal effects in lizards because a generation of ecologists have developed the methods we used.” Sinervo points out that frogs, toads and other amphibians are currently “at huge risk” of extinction, in part due to a fungus that is affecting them. “However, even the spread of the fungus is linked to climate warming by some authors,” the biologist notes. Read the rest of this entry »

Running the numbers

Continued growth in CO2 emissions could lead to dangerous global temperature rises. The red lines represent a "business as usual" scenario that we might already be following, while the blue lines are what is needed to keep emissions below the dangerous 2°C level. Credit M. Meinshausen

Continued growth in CO2 emissions could lead to dangerous global temperature rises. The red lines represent a “business as usual” scenario that we might already be following, while the blue lines are what is needed to keep emissions below the dangerous 2°C level. Credit M. Meinshausen

In 2008, 2010 humans across the world were responsible for emitting greenhouse gases equivalent to 46 37 billion tonnes per year of CO2. In that year there were 6.7 6.9 billion humans on the planet. On average, each human on the planet was therefore responsible for the equivalent of 6.9 5.3 tonnes of emissions. Joeri Rogelj, who spoke to Simple Climate last week, suggests that by 2020 emissions should not exceed the equivalent of 44 billion tonnes per year of CO2. By that time the UN anticipates the world population reaching 7.6 billion, in its medium-growth level prediction scenario. This would mean a cut in emissions to of 5.8 tonnes per person.

The Kyoto protocol and subsequent negotiations have focussed on 1990 as the base year from which to reduce emissions. Rogelj and his colleagues estimate that in that year greenhouse gases equivalent to 36 billion tonnes of CO2 were emitted. Until shortly before the end of the negotiations for the Copenhagen Accord in December, the draft agreement still contained targets specifying a global reduction of 50% below 1990 emissions levels by 2050. This would amount to just 18 billion tonnes of CO2 emissions annually. These kind of targets are seen as necessary for keeping global temperature rises below the 2°C level beyond which climate change would be dangerous. In 2050, the UN’s medium population growth scenario predicts 9 billion people on the planet, meaning that average emissions per person would be just 2 tonnes per year. Read the rest of this entry »

Lots of shoes make for big carbon feet

China is by far the largest "exporter" of carbon dioxide emissions, as seen in this map of the net flow of emissions embodied in trade among the major exporting and importing countries. Arrows indicate direction and magnitude of flow; numbers are megatons (millions of tons). Credit: Steven Davis/Carnegie Institution for Science

China is by far the largest “exporter” of carbon dioxide emissions, as seen in this map of the net flow of emissions embodied in trade among the major exporting and importing countries. Arrows indicate direction and magnitude of flow; numbers are megatons (millions of tons). Credit: Steven Davis/Carnegie Institution for Science

Goods bought in the richest parts of the world effectively export CO2 emissions to poorer countries, a factor overlooked by governments’ climate change strategies. That’s the message coming from research in the news this month performed by two separate groups of researchers, one in the US and one in Norway. The Norway-based team of Edgar Hertwich and colleague Glen Peters in particular note that the carbon footprint continues to grow steadily in parallel with how much consumers spend. “There is no flattening out, no indication that the carbon footprint stabilizes at some point,” they write. Consequently, as nations continue to strive to raise their wealth, we might expect their carbon footprint to grow along with it. “This is, I’m afraid, bad news,” Peters and Hertwich say. “We cannot expect that emissions are reduced as a part of normal development.”

Hertwich and Peters last week won an award for the “Best Policy Paper” for 2009 from the journal Environmental Science and Technology that published their work. They looked at all countries’ carbon footprint in 2001, going further than just looking at CO2 produced within their borders to also assess the impact of international trade for the first time. Their results have been made into a website, called “Carbon Footprint of Nations”, which shows how emissions vary with consumption. Greenhouse gas emissions rise about 70% with each doubling of consumer spending, with more emissions coming from transport and consumer goods and less from food.

 The "Carbon Footprint of Nations" website created by Edgar Hertwich and Glen Peters shows international emissions in 2001.

The “Carbon Footprint of Nations” website created by Edgar Hertwich and Glen Peters shows international emissions in 2001.

On March 8 Ken Caldeira and Steven Davis at the Carnegie Institution in Stanford, California, also published a similar analysis of carbon footprints in 2004 in the Proceedings of the National Academy of Sciences. The study finds that, in 2004, 23% of global CO2 emissions, or 6.2 billion tons, were used to produce goods traded internationally. Per person, about 2.5 tons of CO2 are consumed in the U.S. but produced somewhere else. For Europeans, the figure can exceed four tons per person. Most of these emissions are outsourced to developing countries, especially China, where 22.5% of  the CO2 produced was for goods to be exported. “There is little evidence that carbon-intensive industries are being sited in developing countries in direct response to climate policy,” Caldeira and Davis write. “However, industrial expansion occurring in those countries may unintentionally undermine ongoing efforts to regulate emissions.”

“Where CO2 emissions occur doesn’t matter to the climate system,” Davis says. “Effective policy must have global scope. To the extent that constraints on developing countries’ emissions are the major impediment to effective international climate policy, allocating responsibility for some portion of these emissions to final consumers elsewhere may represent an opportunity for compromise.”

Hertwich and Peters suggest that improving production efficiency and using more renewable energy when manufacturing goods would also be useful. Nevertheless, they still seem uncertain that this will achieve enough. “If we really want to reduce climate change, it seems like the consumption of goods needs to be limited,” they write. This would not mean a complete halt, however, as the scientists note that consumption by rich households in both developing and industrialised nations is needed.