In spite of a mountain of evidence, politicians are still arguing about how pollution is affecting the planet. When the House Science Committee held a hearing on climate change on March 29, the debate centered on a study showing that 97 percent of scientists agree that burning fossil fuels is a major factor in global warming. But much of the testimony focused on small margins of uncertainty about the causes of changing weather patterns and dismissed concerns over the recent increase of heat waves. Only Michael Mann, brought forward as a witness by Democrats, was there to defend the idea that humans are affecting the climate. MTV News talked to researcher John Cook, who published the aforementioned study in 2013 and currently works as an assistant professor at George Mason University, about why defending science is important for the future of the environment.

[This interview has been edited and condensed.]

MTV News: My first question is kind of a basic one, but I think it's essential for this conversation: What is your working definition of what climate change is?

John Cook: Well, climate change is really just change in a climate system, which includes things such as temperature, precipitation, weather patterns, the amount of heat building up in the ocean, and sea level rise. It's not just global warming, it's the way that the whole climate system is changing and how that affects us.

MTV: According to a frequently referenced paper that you published in 2013, there's about a 97 percent consensus among scientists that human interference is causing global warming and climate change. Why is the agreement almost unanimous among those who study and research climate change?

Cook: There is just such a strong body of empirical evidence pointing to humans causing climate change. [Climate scientists] measure patterns in the atmosphere. We see patterns that uniquely match greenhouse gas warming and rule out natural causes like the sun or volcanoes. For example, we see that the upper atmosphere is cooling at the same time that the lower atmosphere is warming. That's a distinct pattern of greenhouse warming. Satellites measure less heat escaping out to space. We've got a big spike exactly where greenhouse gases absorb heat. So, there's these distinct patterns, and they confirm humans' role and they rule out the natural causes.

MTV: Now, some argue that factors beyond human control also affect climate change. What are some of the arguments people use to counter that consensus?

Cook: The most common alternative to [the factor of] burning fossil fuels is that the sun is the driving force of global warming. And we know that can't be the case for many different reasons. But the simplest is that for the last 50 years, the sun has been cooling. Solar activity has been going down at the same time that [the] global temperature has been going up. So the sun and climate are moving in opposite directions.

But there are other reasons, other lines of evidence that really strengthen our understanding of the fact that the sun can't be causing global warming. I mentioned before that we're seeing cooling in the upper atmosphere at the same time we're seeing warming in the lower atmosphere. If the sun was causing global warming, we'd be seeing warming all the way up, in the upper and lower atmosphere. We see the opposite of that.

MTV: So the 97 percent consensus is based on a model that shows the effects of global warming are caused by the burning of fossil fuels rather than natural phenomena, and that global warming isn't just a normal climate cycle the planet goes through?

Cook: What the climate scientists do with their climate models is they work out what are the contributors to climate change. So they do attribution studies, where they'll see what happens when you put all the different causes into a climate model that matches into [observed] patterns quite well. Then they take out human [interference], and without any greenhouse gases building up in the atmosphere, [the model shows that Earth’s] climate would have steadily cooled over the last century. And obviously it has not. So if you took out humans, if we weren't part of the equation, then climate would actually be going through a slight cooling period at the moment.

MTV: Are we already seeing the results of burning fossil fuels? Or will we see those effects in the next decade, century, or couple of centuries?

Cook: [Climate change] isn't something that's projected decades into the future. It's happening right now and it's happening in this country, in America. It's happening in my home country of Australia, where I just came from. I was just at Norfolk and Virginia Beach a month ago, and went around looking at all the areas that are being impacted by sea level rise. They are experiencing regular flooding where they didn't before. And so they have to spend huge amounts of money, taxpayer money, on raising roads to adapt to this increased climate impact.

MTV: What does it mean for America to go from having a president who was concerned with climate change to now having one who presents climate change as if it were a hoax, or as if there isn't evidence of it? What impact is this change of political leadership having on climate change research and our country’s policies for it?

Cook: That's a conversation that I'm having with scientists every day. I think we'll start to get a clearer picture over the next month or two as the proposed budget from the president has to go through the usual process of [approval]. Part of that budget deals with research funding to investigate climate change. Will that funding be capped? Will it be eliminated altogether? My sense is that it will be reduced — hopefully not too much. I hope it isn't eliminated altogether, that would be terrible. I think that we are going through a difficult time at the moment because it's imperative now that we understand how climate change is going to change our society, our infrastructure, our health. We're basically going to be forced to head into this dangerous time blind if we're not funding the research to understand it better.

MTV: In what ways would potentially eliminating funding for climate science research put us at risk?

Cook: In order to develop good adaptation policies, we need to understand how climate is impacted. We're not talking about [just] global warming and temperature; we need to know what's happening in specific regions. How is sea level rise going to affect a place like Norfolk or Florida, and what [other] areas [will it affect]? Where do they need to raise roads? Where do they need to build sea walls? These are all specific questions that require very high-resolution, well-understood climate models. Increasing the resolution of climate models right down to specific areas is really at the cutting edge of climate research right now. If that research is not allowed to continue, then it will become a real struggle to develop specific practical adaptation policies.

MTV: What sort of policies would be ideal to address climate change?

Cook: Well, the number-one thing we need to do is mitigation before adaptation. [Eventually] we're going to have to adapt to climate effects, because some climate change is unavoidable at this point. But the saying that “an ounce of prevention is worth a pound of cure” really applies here. It's much cheaper to spend money avoiding climate change than it is trying to deal with the outfall. So the more we can invest in reducing CO₂ emissions, reducing our pollution now will cost us a small amount compared to the much larger costs down the track if we have to adapt to climate effects.

MTV: What impact could we have, if any, if we did put regulations in place to reduce carbon emissions, to reduce the amount of CO₂ in the atmosphere?

Cook: So now, taking a step back and looking at the broader picture, the IPCC [Intergovernmental Panel on Climate Change] proposed a number of different scenarios. Really, I guess, you're looking at two possible paths. But generally speaking, you have business as usual, where we just continue to burn fossil fuels and not deal with climate change. And you have a path where we try to adapt, we try to mitigate, we try to really change our directory and transition away from fossil fuels and essentially become a zero-carbon society by roughly the middle of the century.

Now, the difference between those two paths is the difference of about four degrees Celsius. That is all the difference in the world. That is the difference between meters and meters of sea levels rising in the next century. It's the difference between parts of the planet becoming uninhabitable — it'll be too hot. It's the difference between precipitation and drought becoming so intense that agriculture is negatively impacted versus being able to continue to do agriculture in the regions [where] we're doing it now. If we go two degrees warmer above pre-industrial temperatures, that's [still] really taking us into dangerous territory. So it's really: Are we willing to go into this dangerous territory, and deep into it, if we continue business as usual? Or are we going to transition our society to zero carbon and stay under the safe limit?

MTV: It's a very daunting issue for a lot of people to wrap their heads around. Is there anything that the average person can do to defend this research and have a positive impact on the future of our environment?

Cook: Yeah, there's a lot of things people can do to contribute. In the immediate sense, participate in the March for Science on April 22. That's in D.C., but there's going to be marches for science happening all over the country. So you can look that up at marchforscience.org. More generally speaking, I think that the main thing we can do is talk about this issue. We published a survey here at George Mason University when we found that even the people who are concerned about climate change, who accept the science and are concerned about impacts of climate change, don't really talk about it that much. We need to make this an issue that people are hearing about. Talking about it with friends and family is important, and talking about this issue to our elected officials is important. Let our politicians know that we care about this issue and we vote based on this concern. Give them the message that voters care about climate change, and suddenly they'll start caring about climate change as well.