Are there natural processes that will amplify or limit global warming?
Yes. Changes in one part of the climate system trigger processes that may either amplify the initial change or counteract it. With a positive climate feedback, warming triggers a process that causes more warming. With a negative climate feedback, warming sets off a process that leads to cooling. The most fundamental negative (cooling) feedback is that the Earth radiates heat into space based on its temperature. The relationship between temperature and radiated heat is such that an increase in temperature is accompanied by an even bigger increase in radiated heat. The feedback does not prevent temperature from rising, but it allows the Earth to return to an equilibrated (balanced) state. The other key feedbacks are water vapor, snow and ice, and clouds. Warming temperatures increase the amount of water vapor in the atmosphere. Because water vapor is a powerful greenhouse gas, it amplifies warming. Decreases in snow and ice make the Earth less reflective to incoming sunlight, also amplif
