CONTENTS
2 How do scientists know that recent climate change is largely caused by human activities?
3 CO2 is already in the atmosphere naturally, so why are emissions from human activity significant?
4 What role has the Sun played in climate change in recent decades?
6 Climate is always changing. Why is climate change of concern now?
7 Is the current level of atmospheric CO2 concentration unprecedented in Earth’s history?
8 Is there a point at which adding more CO2 will not cause further warming?
9 Does the rate of warming vary from one decade to another?
CLIMATE CHANGE Q&A (continued)
11 If the world is warming, why are some winters and summers still very cold?
12 Why is Arctic sea ice decreasing while Antarctic sea ice has changed little?
14 How fast is sea level rising?
15 What is ocean acidification and why does it matter?
16 How confident are scientists that Earth will warm further over the coming century?
17 Are climate changes of a few degrees a cause for concern?
