Call to action needed for polar bearsPosted on 02/08/10
ASHEBORO - Polar bears need our immediate help. Their ability to live, thrive and survive is being threatened by current and projected changes in their environment. While estimated timelines vary, most scientists agree that, unless there are positive changes, polar bears will be unable to adapt and will disappear from the Arctic in a relatively short period of time.
Most of us have heard the terms: global climate change, global warming, Arctic warming, greenhouse gases, greenhouse effect and carbon footprint. Most of us are also aware that these are controversial issues with many varying opinions, as recently demonstrated by the Copenhagen Denmark Summit. Global climate change is the actual and projected changes in temperature, weather and climate, and effects on plants, animals and mankind. For the purpose of this article, let's concentrate on Arctic warming.
Much of the controversy of this subject centers on the causes of global and Arctic warming. Is this the earth going through a natural cycle or is it caused by the activity of man? Scientific data collected over the last several decades is very clear that the activity of mankind has, at the very least, significantly accelerated the warming of the climate. In addition, the Arctic region is warming an estimated three times faster than the rest of the planet.
The basic cause of Arctic warming is a buildup of carbon, in the form of carbon dioxide, in the atmosphere. This buildup causes a greenhouse effect. The sun's energy penetrates the atmosphere and warms the earth. This warmth radiates upward, is trapped by the carbon layer and not allowed to escape from the atmosphere--as it should. This trapped heat energy causes warming. Fossil fuel emissions are the primary source of atmospheric carbon dioxide. Sources such as automobiles, heating, factories, etc. add to the amount of carbon put into the atmosphere, and the level is steadily rising.
A secondary source for atmospheric carbon is deforestation. Trees and other plants draw in carbon dioxide from the air and produce oxygen through photosynthesis. As rainforests and other forests and lands are cleared of trees worldwide, the earth loses its ability to cleanse the atmosphere. More carbon is going into the atmosphere while less is being removed by the natural process of plants. As a result, we are quickly approaching a level of atmospheric carbon that will have catastrophic results if not first leveled off and then reversed.
So how is Arctic warming affecting polar bears? Polar bears need ice to survive. Simply put, no ice equals no bears. The primary food source for polar bears is the ringed seal. Polar bears must wait for ice to form to find and hunt the seals. Without ice, they would be unable to access their food source. Polar bears also mate and give birth to their cubs on the ice. Females with new or first-year cubs will make a den in the ice and spend the worst part of the winter there since these cubs are not yet strong enough for the worst part of the winter. Without this protection, the cubs would perish.
The effects of warming have already had a well-documented and significant impact on the ice of the Arctic region and the bears there. For many years, numerous scientists have studied the situation from varied standpoints. Climate, polar bear predation, reproduction, behavior and health as well as seasonal ice and long-term ice have all been studied independently. Study results capture a common theme: the ice is disappearing rapidly and the effects on polar bears have already become significant in the more southern regions with expectations that these effects will continue to progress northward.
Seasonal ice is that which forms in the winter and melts in the spring. Bears wait for the ice to form and then head out for their season of hunting. As winter ends, bears return ashore to wait for the next winter. They may find food from time to time, but for the most part, this is a period of fasting until the next winter. It is critical that their hunting be successful to build up body stores of fat to survive. Research is showing that the seasonal ice, on average, is forming three weeks later and melting three weeks earlier, thereby cutting short the time bears have to feed. Scientists are finding that many bears are coming ashore in poor condition, especially in the more southern range of polar bears where the change in seasonal ice is already dramatic. Undernourished females are having smaller litters, and the survival rate of cubs is dropping since some females have not fed enough to produce enough milk to support the cubs. Long term ice, which bears reach via the seasonal ice, is also decreasing. Pictures taken over 30 years with satellite imagery show the ice is shrinking and is an estimated 40 percent thinner.
As stated before, polar bears must have ice to survive. As a top predator, polar bears are a very specialized animal, making them more vulnerable to change. Nature finds a way for life to adapt, but such adaptations can take decades or centuries. The environment in the Arctic is changing much too fast and bears have no time for such adaptations. It is estimated that with the current rate of increase of atmospheric carbon dioxide, a "tipping point" could be reached in 5-7 years where the level is so high that seasonal ice cannot form. Long-term ice could be gone, by some estimations, within 5-20 years. If this happens, southern populations of polar bears will quickly decline, followed by the northern populations, in a short period of time.
That's the bad news, but there is hope and action that we can take. We must reduce our carbon footprint. It has taken decades to create the problem of greenhouse gases and, even with appropriate action, it will take decades to correct. But we do not have to eliminate atmospheric carbon to save the polar bears and put the earth heading in the right direction. We need to stop the increase, level it off and not reach that "tipping point" where ice cannot form. Most scientists agree that this is an achievable goal with immediate and decisive action.
Most of us are already aware of how we can reduce our carbon footprint. We need to reduce emission of carbon dioxide and increase the reabsorbtion of carbon dioxide already in the atmosphere. Reduce emissions, for example, by buying the vehicle with the best gas mileage in the type of vehicle you need. Saving energy reduces emissions since many types of production of electricity produce carbon dioxide. Recycle and buy recycled products. Some bottled water containers, for example, are petroleum-based and therefore connected to emissions in their production. Discourage deforestation and encourage reforestation. Plant trees and participate in organized tree-planting events. And finally, spread the word and encourage others to do the same. No one can do it alone. There are many ways to take the actions just mentioned, and the possibilities are too numerous to list here. There are a multitude of organizations and websites that can give excellent suggestions on reducing emissions, saving energy, recycling and reforestation.
The future of polar bears is in our hands. There is no risk to the action steps just described, there can only be positive results. Effects will not be immediate, and polar-bear populations will decline, but hope does remain if we take immediate action. Working together, we can make a difference and ensure that polar bears survive for generations to come, and the actions that save polar bears will surely improve countless other issues on the planet that are ultimately affected by global climate change.
For more information on polar bears, the science of global climate change and what we can do to decrease our carbon footprint, please visit the following websites.
The zoo is an agency of the N.C. Department of Environment & Natural Resources, Dee Freeman, Secretary; Beverly Eaves Perdue, Governor.