A、It will take a long time before a consensus is reached on its impact. B、It would be more costly to deal with its consequences

W: Professor Henderson, could you give us a brief overview of what you do, where you work and your main area of research?
M: Well,(1)the Center for Climate Research where I work links the science of climate change to issues around economics and policy. Some of our research is to do with the likely impacts of climate change and all of the associated risks.
W: And how strong is the evidence that climate change is happening that it’s really something we need to be worried about?
M: Well, most of the science of climate change, particularly that to do with global warming, is simply fact. But other aspects of the science are less certain or at least more disputed. And so we’re rarely talking about risk.(2)What the economics tells us is that it’s probably cheaper to avoid climate change—to avoid the risk—than it is to deal with the likely consequences.
W: So what are we doing? What can we do about it?
M: Well, I would argue that we need to develop the science specifically to understand the likely impacts of climate change in different contexts. As I said, we need to understand the best ways of avoiding climate change.(3)And this will involve a huge transition to low-carbon energy systems. And the transition is a tremendous priority. And for this to happen, we may need action on a global scale. From a political perspective, we need to understand the terms on which major countries like China and the USA might sign up to a global agreement, because at the moment we don’t have that consensus.
W: Right.
M:(4)And we also need to plan ahead so that we are in a position to deal with the likely levels of climate change which are already inevitable, and even more so, too, for the levels that are likely if we don’t get those global agreements.
Questions 1 to 4 are based on the conversation you have just heard.
1. What does Professor Henderson say about his main area of research?
2. What does Professor Henderson say about climate change?
3. What does Professor Henderson say is a top priority in combating climate change?
4. What does Professor Henderson advise us to do to better deal with climate change?