Floods. Droughts. Heat waves. Massive storms. Climate change is not just about polar bears, the iconic symbol of a melting Arctic. It has a profound impact on people, too—with effects that will intensify unless we reduce greenhouse gas emissions.
Climate warming acts like a performance-enhancing drug on the global climate system—making extreme events more likely and more damaging. In fact, if our chief scientist, Dr. Steven C. Amstrup, had his way, every news report on the latest weather disaster would end with these words:
"Events like these will continue to increase in number and severity as the world continues to warm."
Greenhouse gases (GHGs) in the atmosphere act like a blanket that keeps the earth warm. This protective blanket helps make our planet habitable. But over the past 200 years, humans have greatly increased the level of GHGs in the atmosphere by burning fossil fuels like oil and coal. This is like throwing on a second blanket, causing temperatures to rise.
Other factors such as deforestation have added to the problem. Trees soak up carbon dioxide, one of the greenhouse gases, from the air. Fewer trees, especially in the tropics, means less CO2 is removed from the atmosphere.
Warming also leads to more warming as feedback loops start to contribute. Examples include:
- Less ice reflecting less energy back into space
- More open water absorbing more heat,
- Warmer temperatures that thaw ancient permafrost (frozen soils), releasing yet more greenhouse gases
The laws of physics dictate that the world will grow warmer and warmer as greenhouse gas concentrations rise. There's no uncertainty about this: scientists have understood the correlation for over a hundred years. Venus is a perfect example of a planet swaddled thickly in greenhouse gases and too hot.
Are scientists still debating climate change? No. Over 97% of climate scientists—the experts in their field—agree that human activities are causing the current warming and related climate disruption.
The important point to remember is that natural fluctuations in the climate system will continue with global warming, but the baseline will climb higher and higher. This means that scientists can't confidently predict, for example, the first year it will be too hot to grow wheat in Kansas or the first summer the Arctic will be ice-free. But crossing both thresholds is assured unless we reduce greenhouse gas emissions.
And once we cross those thresholds, it will be bad news not only for polar bears—but countless other species, including humans.
Polar bears have evolved for a life on the sea ice, which they rely on for reaching their seal prey. But the arctic sea ice is rapidly diminishing due to a warming earth, affecting the entire arctic ecosystem, from copepods to seals to walruses. For polar bears, sea ice losses mean:
- Reduced access to food
- Drop in body condition
- Lower cub survival rates
- Increase in drowning
- Increase in cannibalism
- Loss of access to denning areas
Scientists predict that as the Arctic continues to warm, two-thirds of the world's polar bears could disappear within this century.
Humans have caused this problem, and humans can fix it. Research suggests that time remains to conserve polar bears if we act soon to greatly reduce greenhouse gas emissions. This means all of us—individuals, communities, businesses, and governments—must work together now. Join us in playing a role to ensure a future for polar bears.
Taking action now won't result in an immediate stop to climate change, but new studies show that we could see the effects in about a decade. Your actions today will help prevent potentially catastrophic changes from taking place—not only helping polar bears, but preserving the climate that has allowed humans to flourish.