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What do you need to know about climate?

What do you need to know about climate in order to be in the best position to adapt to future change? This question was discussed in a European workshop on Copernicus climate services during a heatwave in Barcelona, Spain (June 12-14).

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Why global emissions must peak by 2020

Filed under: — stefan @ 2 June 2017

(by Stefan Rahmstorf and Anders Levermann)

In the landmark Paris Climate Agreement, the world’s nations have committed to “holding the increase in the global average temperature to well below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 °C above pre-industrial levels”. This goal is deemed necessary to avoid incalculable risks to humanity, and it is feasible – but realistically only if global emissions peak by the year 2020 at the latest.

Let us first address the importance of remaining well below 2°C of global warming, and as close to 1.5°C as possible. The World Meteorological Organization climate report[i] for the past year has highlighted that global temperature and sea levels keep rising, reaching record highs once again in 2016. Global sea ice cover reached a record low, and mountain glaciers and the huge ice sheets in Greenland and Antarctica are on a trajectory of accelerating mass loss. More and more people are suffering from increasing and often unprecedented extreme weather events[ii], both in terms of casualties and financial losses. This is the situation after about 1°C global warming since the late 19th Century. More »

Recycling Carbon?

Filed under: — stefan @ 9 May 2016

Guest commentary by Tony Patt, ETH Zürich

This morning I was doing my standard reading of the New York Times, which is generally on the good side with climate reporting, and saw the same old thing: an article about a potential solution, which just got the story wrong, at least incomplete. The particular article was about new technologies for converting CO2 into liquid fuels. These could be important if they are coupled with air capture of CO2, and if the energy that fuels them is renewable: this could be the only realistic way of producing large quantities of liquid fuel with no net CO2 emissions, large enough (for example) to supply the aviation sector. But the article suggested that this technology could make coal-fired power plants sustainable, because it would recycle the carbon. Of course that is wrong: to achieve the 2°C target we need to reduce the carbon intensity of the energy system by 100% in about 50 years, and yet the absolute best that a one-time recycling of carbon can do is to reduce the carbon intensity of the associated systems by 50%.

The fact is, there is a huge amount of uncritical, often misleading media coverage of the technological pathways and government policies for climate mitigation. As with the above story, the most common are those suggesting that approaches that result in a marginal reduction of emissions will solve the problem, and fail to ask whether those approaches also help us on the pathway towards 100% emissions reduction, or whether they take us down a dead-end that stops well short of 100%. There are also countless articles suggesting that the one key policy instrument that we need to solve the problem is a carbon tax or cap-and-trade market. We know, from two decades of social-science research, that these instruments do work to bring about marginal reductions in emissions, largely by stimulating improvements in efficiency. We also know that, at least so far, they have done virtually nothing to stimulate investment in the more sweeping changes in energy infrastructure that are needed to eliminate reliance on fossil fuels as the backbone of our system, and hence reduce emissions by 100%. We also know that other policy instruments have worked to stimulate these kinds of changes, at least to a limited extent. One thing we don’t know is what combination of policies could work to bring about the changes fast enough in the future. That is why this is an area of vigorous social science research. Just as there are large uncertainties in the climate system, there are large uncertainties in the climate solution system, and misreporting on these uncertainties can easily mislead us.

It’s fantastic that web sites like Real Climate and Climate Feedback re out there to clear some of the popular misconceptions about how the climate system functions. But if we care about actually solving the problem of climate change, then we also need to work continuously to clear the misconceptions, arising every day, about the strategies to take us there.

Anthony Patt is professor at the ETH in Zurich; his research focuses on climate policy


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