Climate change is a normal condition for the Earth and the past record suggests continuous rather than stability. The last 2 million years of Earth history are characterised by a series of cold glacial events with warmer intervening interglacial periods. Peatland expanded and contracted with changes in climate and sea-level. Many current peatland started growth following the warming after the last glacial maximum. The initiation of new preatlands has continued throughout the postglacial period in response to changes in climate and successional change.  

The world's peatlands influence the global balance of three main greenhouse gases (GHG) - carbon dioxide (CO₂), methane (CH₄)  and nitrous oxide (N₂O). In their natural state, peatlands remove CO₂ from the atmosphere via peat accumulation and emit methane. The long term negative effect of  methane emissions is smaller than the positive effect of CO₂ sequestratian. By sequestering and storing an enormous amount of atmospheric CO₂ peatlands have an increasing cooling effect in the same way as in former geological eras, when they formed coal, lignite and other fossil fuels.

When peatlands are disturbed, they can become siginificant sources of carbon dioxide and at the same time do not totally stop emitting methane. Methance may still be released drom drainage ditches and in mining operations from milled peat surfaces and peat stockpiles. Drained peatlands, especially after fertilization, can also become an important source of nitrous oxide. Peatland restoration reduces net GHG emissions to the atmosphere, certainly over the long term.