Our Changing Climate

The ‘greenhouse effect’ is warming the planet and causing massive changes in the climate system. Heat-trapping “greenhouse gasses” – largely the result of burning coal and oil – have built up in the atmosphere to levels not seen in at least 800,000 years.



Our Climate’s Instability

Carbon dioxide, or CO2, is released by burning fossil fuels to provide the energy that drives almost every aspect of modern life. It has a long life in the atmosphere, so the build-up of heat-trapping gas is cumulative.

Scientists have said that the safe limit of carbon in the atmosphere is somewhere between 250 and 450 parts per million. Already at 390 ppm, levels are steadily rising. The temperature-regulating mechanisms that have been operating for hundreds of thousands of years have been disrupted.

The geological record warns of past “Tipping Points”, when changing levels of atmospheric carbon coincided with massive changes in the global climate system.  Tipping points interact with other global systems in ways that are unpredictable, but potentially life-threatening.


We must stop warming short of these dangerous “Tipping Points.”

“Embracing a low carbon economy will be as momentous as the previous industrial revolutions. As the shift from coal to oil. And the shift from gas light to electric light. … The scale of the challenge is extraordinary. We will need to reinvent the way we live our lives, the way our world works.” —Charles Hendry



Reducing the carbon emissions (nearly 30 billion metric tonnes in 2010 alone!) that are trapping heat in the atmosphere is of central importance. Energy efficiency and clean, renewable energy are key to solving to this planetary challenge.

• In addition to fossil fuel emissions, human changes to the biosphere are reducing natural “carbon sinks” like forests and wetlands, which keep carbon from entering the atmosphere. Thus protecting earth’s forests and wildlands also helps to safeguard our climate.

Reducing emissions of methane, another important greenhouse gas, is also key to the solution. Methane is a much smaller percent of the gas in the air, but each methane molecule is many times more effective in trapping heat in the earth’s systems. We can stop releasing methane at its sources by reducing the number of cows grazing around the world and by preventing natural gas from escaping in the atmosphere.

• Among other reasons, minimizing further planetary warming is vital to prevent the release of massive amounts of methane from frozen tundra – a potential tipping point that could case the earth’s warming to spin out of control.




Youth Leadership: PowerShift!, a dynamic climate protection community, is organized by and for young people.



Reduce your impact on the earth’s climate by lowering your “carbon footprint”.  Invite your household and workplace to go on a Low Carbon Diet and challenge yourselves to reduce your contribution to global warming pollution by 5,000 pounds of carbon dioxide in 30 days.




National Geographic’s Global Warming Effects Map

For more on the greenhouse effect, see: http://en.wikipedia.org/wiki/Greenhouse_gases