Carbon emissions: Carbon dioxide accumulation
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About half of the carbon dioxide emitted by human activities accumulates in the atmosphere, remaining for over 100 years on average. It’s not the rate of emission but the total amount of carbon dioxide and other greenhouse gases accumulated in the atmosphere that causes the planet to warm. So when considering how fast to reduce emissions rates, and to what level, governments must consider the total greenhouse gas content accumulated in the atmosphere, taking into account historical as well as present-day and future emissions.