How We are Hurting Our World

The current cycle of global warming is changing the rhythms of climate that all living things have come to rely upon. What will we do to slow this warming? How will we cope with the changes we've already set into motion? While we struggle to figure it all out, the face of the Earth as we know it—coasts, forests, farms, and snowcapped mountains—hangs in the balance.

What Causes Global Warming?
Scientists have spent decades figuring out what is causing global warming. They've looked at the natural cycles and events that are known to influence climate. But the amount and pattern of warming that's been measured can't be explained by these factors alone. The only way to explain the pattern is to include the effect of greenhouse gases (GHGs) emitted by humans.

To bring all this information together, the United Nations formed a group of scientists called the Intergovernmental Panel on Climate Change, or IPCC. The IPCC meets every few years to review the latest scientific findings and write a report summarizing all that is known about global warming. Each report represents a consensus, or agreement, among hundreds of leading scientists.

One of the first things scientists learned is that there are several greenhouse gases responsible for warming, and humans emit them in a variety of ways. Most come from the combustion of fossil fuels in cars, factories and electricity production. The gas responsible for the most warming is carbon dioxide, also called CO2. Other contributors include methane released from landfills and agriculture (especially from the digestive systems of grazing animals), nitrous oxide from fertilizers, gases used for refrigeration and industrial processes, and the loss of forests that would otherwise store CO2.

Different greenhouse gases have very different heat-trapping abilities. Some of them can even trap more heat than CO2. A molecule of methane produces more than 20 times the warming of a molecule of CO2. Nitrous oxide is 300 times more powerful than CO2. Other gases, such as chlorofluorocarbons (which have been banned in much of the world because they also degrade the ozone layer), have heat-trapping potential thousands of times greater than CO2. But because their concentrations are much lower than CO2, none of these gases adds as much warmth to the atmosphere as CO2 does.

In order to understand the effects of all the gases together, scientists tend to talk about all greenhouse gases in terms of the equivalent amount of CO2. Since 1990, yearly emissions have gone up by about 6 billion metric tons of "carbon dioxide equivalent" worldwide, more than a 20 percent increase.
 Arctic Sea Ice Decline

In the Arctic, temperature has increased at twice the rate as the rest of the globe, and could increase by another 8°C (14°F) by the end of this century. The warming atmosphere along with new weather pattern extremes is causing Arctic sea ice to melt at an alarming rate—12% per decade—that suggests the Arctic will be ice-free by 2030. The impacts of dwindling ice cover in the Arctic are far-reaching, from species endangerment to enhanced global warming, to the weakening or shut-down of global ocean circulation.

 

Marooned on land due to lack of sea ice, this bear forages for food at a garbage dump. Although trash can temporarily fill an empty belly, it cannot provide nourishing long-term sustenance. As rising temperatures trap fasting bears on land for longer periods, they are increasingly searching for food in close proximity to people, and that poses risks to both humans and bears.

 

What will it take to make us respond to the tragedy we are creating?  Will we be too late to save any of the living species whose care and custodianship we have been entrusted with ? Will we be too late to save our planet?