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Showing posts from April, 2021

Effects of COVID lockdowns on climate change: figure descriptions

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What does this figure mean? Here's a figure I showed in the main blog post . Let's inspect each element of it closely.     The x-axis is a time axis showing the decade covered by the simulation. The y-axis shows temperature change in ℃. These results are from the two-year blip pathway compared to the baseline pathway. For the curious reader, the baseline assumes that all countries will meet their Nationally Determined Contributions (NDCs) by 2030. It is a central estimate of emissions i.e. neither the best-case not the worst-case scenario. Now note the evolution of each line on the plot. The aerosols, shown in green, first lead to a temperature increase (because they stop shielding the Earth from the Sun's radiation). In the long term, their effect plateaus out because aerosols have a short residence time in the atmosphere. This means that they can not have any long lasting effects because they get removed from the atmosphere. Next, in pink, is tropospheric ozone. Initially...

Effects of COVID lockdowns on climate change

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Simply put: Forster et al. (2020) To control the pandemic, many countries imposed lockdowns last year. While such restrictions led to an obvious dip in air pollution, can we assume they also halted - or even slowed down - climate change? To answer this question, Forster et al. (2020) [ Nature Climate Change ] 1 modelled the effect of these lockdowns on climate change. They developed a new method of estimating emissions changes during the lockdowns using global mobility data from Google and Apple. Combining these with existing estimates of emissions changes from major sectors - power, surface transport, residential, public and commercial, industry, national shipping, international shipping, national aviation and international aviation - they studied changes in ten species of green house gases (GHGs) and air pollutants over the period February - June 2020. Their analysis includes emission changes from 123 countries around the world, which together cover >99% of global fossil fuel CO ...