What we do know - and what we don't

摘要

There is much we do not understand about Earth's climate. That is hardly surprising, given the complex interplay of physical, chemical and biological processes that determines what happens on our planet's surface and in its atmosphere. Despite this, we can be certain about some things. For a start, the planet is warming, and human activity is largely responsible. But how much is Earth on course to warm by? What will the global and local effects be? How will it affect our lives?