Questions & Answers: Climate Change

The following are questions asked of ACMP scientists and the answers they provided. Click on the question at the top to jump to the answer below.

What are we doing to cause global warming?

Global warming has to do with gases that we put into the atmosphere that are really good at trapping heat. For example, if we burn coal, it releases carbon dioxide. Carbon dioxide is a great gas. It's like putting a warm blanket on the Earth. It helps trap heat inside Earth. Instead of heat being radiated back out to space, which would cause Earth to cool, it's trapping the heat near the surface of Earth. So, by putting out gases like carbon dioxide, we are helping trap the heat, which is causing the Earth to warm. We also cause a little bit of cooling. Certain particles can scatter light and reflect it back to space before it gets low in the atmosphere, and that will cause cooling because it's not getting all the way to the surface. - Cathy Cahill

I thought we've been able to discern what the natural cycles are, and that the data is showing that the warming is more than those natural cycles. Isn't the prevailing attitude among climatologists that we are beyond that natural cycle?

My personal opinion is that we are way beyond the natural cycle. Unfortunately, there is still some discussion over what the natural cycle is versus what we have now. It's something that is being debated. A lot of people will say we're beyond the natural cycle, but question if we are seeing the natural cycle plus a little bit of anthropogenic, or a low part of the natural cycle plus a lot of anthropogenic. Trying to tease out which portion is attributable to what is where the debate lies. There are some scientists who don't think that we've exceeded the natural cycle by a whole lot; that we've had quick warming and cooling before in the ice core record; we're just in one of the warm phases right now and we shouldn't be worried that much. I think that most of the scientists would agree that we are well beyond a natural warming, but there have been some significant warming and cooling periods in the ice core record and the naysayers point to those periods in history and say we are not outside the normal. It is currently being argued.-  Cathy Cahill

What natural cycles influence climate?

Several natural cycles influence climate change. Earth changes its orbit around the sun. Sometimes Earth is closer or farther from the sun, which causes temperatures to change. This has caused several ice ages.
Another reason climate changes is the addition of greenhouse gases in the atmosphere, like carbon dioxide. That's what's happening right now. As we burn oil, gas, and wood, it puts carbon dioxide into the air that makes the world warmer. In addition, climate changes all by itself. Climate has small bounces of its own which scientists do not fully understand. - John Walsh

Why is Alaska in the middle of the warming trend?

There are a couple of factors that are causing Alaska to warm so much. One of them is the greenhouse gas factor. The other factor is that there is a shift in the wind patterns. Alaska has recently received more frequent winds from the south, which tend to bring in warmer air and caused warmer winters. This is an example of the natural variability that is in the climate system. - John Walsh

With the technology in existence to move away from gasoline and fossil fuels, why is there not a greater push to move away from those technologies toward other fuel sources?

One of the reasons for the slowness to moving toward alternative energy is the cost to start them up. In order to figure out how to get wind energy or tidal energy to be useful at a reasonable price, it takes a large investment of money at the very beginning. Getting investors and scientists to refine the technology is the first hurdle we have to get over. However, recently it seems that more and more people are seeing the value of alternative energy sources, and it's likely that more and more investments will be made in the near future. - John Walsh

If winter temperatures have raised 9 degrees in the past 50 years does that mean that they will raise another 9 degrees in the next 50 years?

No. The 9 degrees is due partly to greenhouse gas induced global warming and partly to natural climate variablity in the form of changing winds. If the warm winds from the south shift again, we will lose that warmth. If the winds change again, there is a chance that the warming will continue, but not as high a rate. - John Walsh

What builds up greenhouse gases?

Burning coal, oil, natural gas, and wood put greenhouse gases (carbon dioxide in particular) into the air. - John Walsh

Are there any positive outcomes to climate change?

I think so, yes. One is warming of the winters in the really cold areas. Additionally, the growing season in northern climates is getting longer, because summers are getting longer and winters are getting shorter. Additionally, some people argue that as the ice recedes, more marine transportation will increase trade and exploration. - John Walsh

Will there be negative effects of opening up shipping routes along the Northern ice cap?

The negative effects are mainly potential oil spills and possible impacts on marine mammals. There are a lot of environmental impacts studies that need to be done before any shipping is allowed up there. - John Walsh

I hear in the news that polar bears are being considered a threatened species, is this because of climate change?

The reason it is taking so long for the government to make a determination on whether polar bears are threatened or not is due to the fact that they aren't sure if climate change is the only factor at work. There is also the fact that some polar bears are killed by hunters; in some areas that might be more of an effect than climate change. I think most scientists agree that climate change is a factor, but it's not the only one. - John Walsh

Can we reduce the accumulated greenhouse gases in the atmosphere?

Not in our lifetime. What we put into the atmosphere will stay there for hundreds of years. However, we can slow the increase. But, once we slow the increase, it will take centuries for the greenhouse gases in the atmosphere to return to the level they were at just a few decades ago. - John Walsh

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