350 is the world’s most important number.

Leading climate change experts agree that 350 parts per million (350ppm) is the safe upper limit for CO2 in our atmosphere.  We are currently at just about 390ppm, and unless we rapidly return to 350ppm this century, we risk catastrophes like the melting of the Greenland ice sheet and major methane (another major greenhouse gas) releases from increased permafrost melt.

For all of human history until about two centuries ago, our atmosphere contained about 275ppm* of carbon dioxide.  275 ppm CO2 is a useful amount – without some CO2 and other greenhouse gases that trap heat in our atmosphere, our planet would be too cold for humans to inhabit.

Then, beginning in the 18th century, humans began to burn coal and gas and oil to produce energy and goods.  The amount of carbon dioxide in the atmosphere began to rise, at first slowly and now more quickly.  Many of the activities we do every day like turning the lights on, cooking food, or heating or cooling our homes rely on energy sources like coal and oil that emit carbon dioxide and other heat-trapping gases into the atmosphere.  We’re taking millions of years’ worth of carbon, stored beneath the earth as fossil fuels, and releasing it into the atmosphere.  Now the planet has 390ppm CO2 – and this number is rising by about 2ppm every year.

Scientists are now saying that’s too much.  We need to reduce levels and they’re agreeing that 350ppm is the maximum level of CO2 we can have in our atmosphere and not have major global climate change.  The dangers of climate change are huge.  Remember, the climate we have now is the climate on which humans built civilization.  If we change the climate we will change, and likely destroy, civilization as we know it.

Reducing the levels of CO2 will be a hard task, but not impossible.  The most basic thing we need to do is to stop taking carbon out of the ground and putting it into the air.  If we do, then the earth’s soils and forests will slowly cycle some of that extra carbon out of the atmosphere, and eventually CO2 concentrations will return to a safe level.

By decreasing use of other fossil fuels, and improving agricultural and forestry practices around the world, scientists believe we could get back to 350 by mid-century. But the longer we remain in the danger zone – above 350 – the more likely that we will see disastrous and irreversible climate impacts.

Every year since 1992, the United Nations hosts a two-week long conference for world leaders to meet and discuss what to do to about the global threat of climate change.  In December of 2009, this meeting will be in Copenhagen, Denmark.  There, delegates, non-governmental organizations, and businesses from every nation will meet to finalize a new global climate change agreement.

It is crucial that decision-makers at this meeting understand and are held accountable to crafting policy that is informed by the most recent science.  That’s where we come in.  On Saturday, October 24, the will be events around the globe to raise awareness of this issue.  As of the press deadline, there will be 1545 events in 117 countries.  One of them is being organized by the Board of Social Concerns at Niles Congregational Church.

From 11:00 a.m. to 1:00 p.m. that day, concerned people from the region will gather along Marshlands Road in Newark in an effort to build awareness about global climate change.

People will being gathering at 11:00 in parking lot off Marshlands Rd, near Thornton.  Then, at 11:30, people will line up line along Marshlands Rd, looking out over the wetlands that will become part of the San Francisco Bay by 2100 if CO2 levels aren’t decreased to 350ppm.  Hopefully this will also be a time to answer reporters’ questions and to have pictures taken!

Then, at noon, the group can walk up Marshlands Road to the Don Edwards San Francisco Bay National Wildlife Refuge for a bring-your-own picnic lunch.  The public is invited to bring polite signs – things like, “Don’t let this be waterfront property.  Decrease CO2 levels to 350ppm.”  Let’s have the number 350 everywhere!

For more information about this event, go to http://www.350.org/newarkca.

The organizers will also be collecting postcards (our goal is 350) to send to Washington DC as we prepare for the Copenhagen summit.

With your help, we can spread this important piece of information to our fellow citizens, communities, countries, and the world.

* Parts per million is simply a way of measuring the concentration of different gases, and means the ratio of the number of carbon dioxide molecules per million other molecules in the atmosphere.

Copyright © 2009 Jeffrey S. Spencer