Posts Tagged ‘global warming’

This is a make or break moment in our fight against global warming. We must act now to reduce our carbon emissions or we will commit the earth to devastating climate change.

The Environmental Defense Fund interviewed three EDF scientists on the crisis and how important it is that we act now.

EDF: What is the best estimate today of what we’re committed to regarding global warming over the next two or three decades? Is it too late to change anything?

Steve Hamburg: We’re really working hard to limit the impacts of global warming to two degrees Celsius above pre-industrial temperatures. The most important question is when do we actually stop the increase in emissions and start decreasing it? At what point and at what level and then at what rate can we decrease it? That becomes a really critical point.

James Wang: We could in theory remove carbon dioxide from the air and thereby start cooling the climate. Given technical and political realities…a lot of groups are shooting for limiting warming to two degrees Celsius above pre-industrial levels. This is a level that many scientists consider to be a threshold, above which we’re going to have really serious irreversible impacts, like the meltdown of the Greenland Ice Sheet, which would raise sea level by over 20 feet.

EDF: At two degrees what kind of visible impacts can people expect?

Lisa Moore: At two degrees, as James mentioned, there is certainly big concern that the Greenland Ice sheet will be committed to full disintegration over the next several centuries. The tipping points might come earlier or maybe we will be lucky and they will come later. The Greenland Ice Sheet certainly gets a lot of attention. Some of the tipping points that scientists are talking about involve total disappearance of summer sea ice in the Arctic Ocean, really widespread extinctions of earth’s plants and animals and dramatic changes in whole ecosystems. Various species have temperature ranges that they can tolerate. If they cannot move to new places because either there are no places available to them or they can’t get there fast enough as the temperatures and other conditions change and if they can’t tolerate those new temperatures they will die off. There are some species that are more vulnerable than others, but biologists are seriously discussing really scary numbers, including one-third of species going extinct.

SH: One of the things that we have to think about, which is fundamentally different than what has happened historically with the record of climate change over the past millions of years, is that now the surface of the earth has large numbers of human-caused alterations—roads, agriculture, forestry, housing—those are all impediments and alterations to the way species can migrate. It is important to remember that species migrate through their offspring and their seeds. The individuals are seldom the ones that are migrating, or they go a little distance and their offspring go a little further. Our best guess for what the rates are don’t include humans, so in some cases humans are helping because things attach to cars and attach to boats and so they spread faster. In other cases their dispersal is negatively impacted, for example by an interstate they are not going to get across.

LM: Remember that all species depend on others, so when one is impacted another will feel those effects. Think about when plants bloom; when leaves fall; when birds migrate. As that timing changes, species respond differently and they can get out of sync with each other. Interactions among species are going to ripple out to affect whole ecosystems. Again, there are really big uncertainties around the details, but very, very good reasons to expect very large changes. Another big concern is ocean acidification. CO₂ doesn’t just cause warming, it also dissolves into the ocean where it forms carbonic acid and the oceans are acidifying at a rate that marine organisms haven’t seen in their evolutionary history. It is extraordinarily rapid and there are reasons to believe it could have really bad effects on coral reefs, other shell-forming organisms and all of the food chains that they support.

SH: Even if we accomplish what many now believe is going to be a big challenge maintaining, keeping climate change to within two degrees Celsius, one of the most vulnerable ecosystems in the world will be coral reefs.

EDF: What kinds of changes might people in the United States have seen in their own back yards if they’ve been paying attention?

SH: We’re actually developing two museum exhibits on this issue: one for New England and one for North Carolina. In New England we are using three iconic issues: One is maple syrup production—maple syrup producers’ seasons start earlier and they have to use more technology to maintain their production. These farmers will no longer be able to produce syrup commercially because the winter won’t be sufficient to support it—they need the snow, cold temperatures during nights and warm temperatures during the day. The nights are not getting cold enough to produce the sap runs needed for maple syrup production.

Second, you’re going to see more invasions in central New England of red oaks, which are present in southern New England. Everyone enjoys the fall foliage—particularly magnificent with the inclusion of bright oranges for sugar maple and the reds for red maple. The oaks have much more brown and those will diminish the quality of that experience. I have personally seen the invasion of oaks up the side of a mountain over the course of my research career. The oaks are present in places they weren’t 25 years ago and it is directly attributable to climate change.

Third, lobster fisheries are moving north as a result of temperature changes; places that supported a vibrant lobster industry in Long Island Sound 50 years ago are now seeing very limited takes and will soon be completely gone. North Carolina has similar issues within the crab fisheries. The Balsam Fir Christmas tree trade is also being threatened; the trees just can’t thrive and grow in an area in the western part of the State.

LM: Some other examples include the snow pack in the west, which has been decreasing for at least the last five decades; it is starting to melt earlier and earlier. The evidence for that is very clear. The Audubon Society recently put out a report about how bird patterns are changing in North America. Gardeners are also feeling the effects. In fact, in 2006, the Arbor Day Foundation actually re-drew the hardiness zones for the United States because of documented climate changes.

JW: Also, there’s been a trend of larger and more destructive wildfires in the West and there have been studies showing that not only has the area of wildfires increased over time in recent decades, but also these fires are moving up higher in altitude to areas that had previously experienced little fire, so this shows that it’s not just a consequence of our forest management practices, namely suppression of fires in the past, but it’s also influenced by climate change. In the year 2000, the west experienced its worst wildfire season in 50 years and in more recent years we’ve seen record destruction from wildfires in California.

EDF: What is your answer to individuals out there who ask, “What can I do?”

LM: People should educate themselves about the issues. They should tell their elected representative that this is an important issue for them, vote accordingly, take whatever steps they’re able to take and make lifestyle changes that are better for the environment, whether that’s being better about turning off the lights when you leave the room, or replacing your light bulbs with energy efficient bulbs, or turning down your thermostat. And all the little things that people probably have heard over the years, those things really do add up if you adopt those changes. From a large-scale perspective, putting pressure on governments and corporations to make large-scale changes is really important.

JW: A personal favorite solution of mine is for people to purchase renewable electricity—it is in fact available in most states in the U.S. now, so the argument that we don’t have that option is not valid. Here in New York State, for example, I purchase 100% wind power for my apartment, and I think more people ought to do that. It doesn’t necessarily cost that much more than conventional fossil fuel-powered electricity. And the greater the demand for renewable energy, the more renewable resources will be developed to meet demand. This is basic economics. Of course, a national cap on emissions would give a tremendous boost to demand for renewable energy.

EDF: How do you engage children in the issue of climate change? Are many young people familiar with climate change science?

JW: Lisa and I have made presentations in front of school children before, talking to them about what global warming is and what they can do about it.

LM: I’ve spoken in schools, I’ve gone to community science events, I’ve given information to teachers to pass on to students. My experience is that the students have heard about it, they’re concerned about it and they’re open and engaged, which gives me hope. Now if we can just get them to vote when they’re of age, that would be great! But yes, the young people that I’ve talked to about this issue are familiar with it. They may have some misconceptions, they may not know all of the facts, but they know it’s a problem, they know that humans are the cause and they know that there are things that we can do about it. So, that’s definitely a cause for some optimism.

EDF: Is there one thing that you wish every American could know about Global Warming?

JW: I’d say that a few degrees of warming might not seem like a lot, but people should realize that the difference in global temperature between the last major Ice Age, when the ice sheet in North America went all the way down to New York City, and the present time is only about five degrees Celsius or nine degrees Fahrenheit. And we’re expecting that if we don’t do anything about global warming, the Earth is going to warm by about that much over the next century. So the world will be completely different. This is a very, very serious problem. I’d like to add that on the flip side it’s something that we can solve; we can do something about global warming, so we really need to be concerned and working on this.

EDF: How do you get up and do what you do, knowing what you know? There is so much information on climate change that is disturbing and upsetting. How do you do it every day?

SH: I think you’ll find that most of the people who work on climate change impacts are inherently optimistic individuals. We realize that both human systems and natural systems are resilient, so we have faith that humans, once they really understand these impacts, will make the changes that they need to make; and we recognize that while we may suffer a lot of losses in the natural world, that we’ll also get some positive surprises and hopefully that human society will respond quickly enough so that those losses are not overwhelming. It can be bleak if you think about it rationally and what it’ll be like for my grandchildren. You have to be an optimist; you have to have faith that humanity will recognize the threat that’s before them and they’ll respond.

JW: I guess what motivates me is that I know that many other people are working on the issues—environmental problems in general and climate change in particular—and so it’s definitely a team effort and eventually we’ll get it solved. This has happened for various other issues in the past, like civil rights or like various other problems. I think there’s definitely hope for the environment.