Peatlands have been absorbing CO2 for a long time, helping cool the climate. But as the North warms up quickly, the CO2 absorption of peatlands is changing. Warmer early summers make peatlands take in more CO2, while warmer late summers make them take in less. This means that peatlands in places like central Siberia, where summers warm up early, are more likely to keep absorbing CO2 in a warmer climate. The timing of summer warming affects how much CO2 peatlands can absorb, with early warming leading to more absorption and later warming leading to less.