THE BLOG

Top Climate Scientists Urge Action in Run Up to Historic Meeting

07/11/2009 05:12 am ET | Updated May 25, 2011

Representatives of the world's governments are in Bonn, Germany this week to begin negotiating what may be one of the most important deals of our times.

The Bonn climate talks are the first big step towards a very large and historical meeting that will take place in Copenhagen in December of this year. The Copenhagen United Nations Climate Change Conference - or in UN lingo "COP 15" - will be venue for the world's governments to decide on how aggressively the human race will work to reduce greenhouse gas emissions that leading scientists are telling us are the cause of climate change. Copenhagen is literally ground zero and will determine the pathway civilization will take for the next 50 or so years.

Obviously this is not a meeting to be taken lightly and a group of top scientists have issued an open letter today urging the negotiators in Bonn to put strict limits on the cumulative emissions of carbon dioxide, which is the main culprit that is heating our planet.

"In addition to setting targets for emissions in 2020 and 2050, we feel the UNFCCC process should acknowledge that avoiding dangerous climate change will require emissions of the longest-lived greenhouse gases like carbon dioxide eventually to cease altogether," says Dr. Myles Aleen of Oxford University's Department of Physics.

Scientists are normally a very leveled bunch, not inclined to step into the policy ring, but quite frankly, how much more science do we need to be convinced that this is a huge problem, especially when we're already witnessing the predictable effects of climate change all over the world?

The negotiators in Bonn are being watched very closely for what they do (and don't do) in this current round of negotiations, as the outcome here will be a very good indicator of what will happen at the Big Show in Copenhagen.

Here's a full copy of the Scientists Open Letter to the Bonn negotiators:

The need to limit cumulative carbon dioxide emissions to avoid dangerous climate change

We welcome the efforts of governments around the world to reach agreement on measures to reduce greenhouse gas emissions, and wish to draw attention to recent scientific research indicating that a key determinant of the risk of dangerous climate change is cumulative emissions over all time of the longest-lived greenhouse gases, in particular carbon dioxide. This has three important implications:

First, current emission trends are incompatible with the goal of limiting cumulative emissions to a level that provides an acceptably low risk of dangerous climate change. Estimates of tolerable risk and allowable emissions vary, but in all cases costs rise sharply with the speed of emission reductions, so any affordable strategy to avoid releasing too much carbon dioxide in total will require global emissions to peak soon.

Second, in devising emission targets for 2020 and 2050, governments need to be aware of their implications for cumulative emissions. A policy that allows carbon dioxide emissions to rise over the coming decade in the hope of reducing them rapidly after 2020 results in a substantially higher contribution to the cumulative budget, and hence a greater contribution to the risk of dangerous climate change, than a policy of steady reductions reaching the same 2050 target.

Third, fossil carbon reserves substantially exceed the amount that can safely be released into the atmosphere. Net global carbon dioxide emissions will eventually have to decline towards zero leaving a substantial fraction of available fossil carbon stored, in some form, out of the atmosphere indefinitely.

We urge the participants in December's Conference of the Parties to the United Nations Framework Convention on Climate Change to acknowledge the need to limit cumulative carbon dioxide emissions as one element of their vision for long-term cooperative action to avoid dangerous climate change.