Climate change could fuel a giant ‘compost bomb’ … as decaying vegetation stuck under under the ice or in peat bogs starts to heat up and tips the world into dangerous global warming.

“Scientists fear that if temperatures warm up too fast peatland soils will heat up like a compost heap and release billions of tonnes of carbon into the atmosphere.”

The Planet Under Pressure conference began with an urgent warning of fast-approaching tipping points like the “compost bomb.” It ended with a plea by the conference leaders for urgent and large-scale action.

The conference website reports, “Scientists issue first ‘State of the Planet’ declaration at the world’s largest gathering of experts on global environmental and social issues in advance of the major UN Summit Rio+20 in June.”

The language is unusually blunt for scientists — or it would have been considered unusually blunt before humanity chose to ignore decades of warning by scientists (see Lonnie Thompson on why climatologists are speaking out: “Virtually all of us are now convinced that global warming poses a clear and present danger to civilization”).

The statement begins:

Research now demonstrates that the continued functioning of the Earth system as it has supported the well-being of human civilization in recent centuries is at risk. Without urgent action, we could face threats to water, food, biodiversity and other critical resources: these threats risk intensifying economic, ecological and social crises, creating the potential for a humanitarian emergency on a global scale….

The defining challenge of our age is to safeguard Earth’s natural processes to ensure the well-being of civilization while eradicating poverty, reducing conflict over resources, and supporting human and ecosystem health….

As consumption accelerates everywhere and world population rises, it is no longer sufficient to work towards a distant ideal of sustainable development. Global sustainability must become a foundation of society. It can and must be part of the bedrock of nation states and the fabric of societies.

While some bloggers have tried to suggest that this statement endorses a do-little, R&D-centric approach, in fact the reverse is true. The statement makes clear, “Society is taking substantial risks by delaying urgent and large-scale action.”

Further, the Conference’s Board of Patrons — 18 leading figures including scientists, CEOs, and major politicians — took the unusual step of endorsing the entire statement and adding their own blunt assessment:

The Board of Patrons welcomes and endorses the Conference statement.

The human species is degrading the environment at all spatial scales, from local to global. Scientific understanding of environmental deterioration has improved and deepened since the Rio Earth Summit in 1992, but society has failed to address environmental degradation at a scale the problems require. We have to manage the planet as the biophysical system that it is and for all the promise that it holds. The survival of our societies, our civilization and our cultures are dependent on a stable climate, natural resources and ecosystem services. We have become a force of nature, but individually we continue to be vulnerable. Business-as-usual is not an option. The time for action is now.

Our civilization is at stake.

The UK Telegraph reported on one of the openings talks that underscored that point, ” ‘Compost bomb’ is latest climate change ‘tipping point’ “:

Scientists fear that if temperatures warm up too fast it will destabilise these natural cycles and unlock billions of tonnes of greenhouse gases into the atmosphere.

Peatlands cover just 3 percent of the world’s land area, but the soil could store up to twice the amount of carbons currently in the atmosphere.

Peter Cox, Professor of Climate System Dynamics at the University of Exeter, explained the process of decomposition kicked off by warmer temperatures.

He said microbes in the soil generate more heat as they break down vegetable matter, releasing a certain amount of gases until the “compost heap” is exhausted or temperatures cool

However if temperatures rise too fast there is a “runaway effect” as the microbes are producing heat so fast it cannot be released and builds up, potentially causing fires. Gases also build up eventually causing a huge ‘burp’ or explosive release of carbon into the atmosphere all at once….

“But if we are warming the planet too fast then theoretically the soils will warm up like a compost heap, making the microbes work faster and generate yet more heat. This causes heat and gases to build up and an abrupt release of carbon into the atmosphere.”

The compost bomb also causes a positive ‘feedback loop’ as the hotter the soil gets the harder the microbes work, causing yet more heat. Also the gases released cause more global warming.

For background, see NSIDC: Thawing permafrost feedback will turn Arctic from carbon sink to source in the 2020s, releasing 100 billion tons of carbon by 2100 and Stunning Peatlands Amplifying Feedback: Drying Wetlands and Intensifying Wildfires Boost Carbon Release Ninefold.

Speaking at the Planet under Pressure conference in London, Prof Will Steffen, a global change expert from the Australian National University, described the ‘compost bomb’ as one of many “tipping points” in danger of pushing global temperatures beyond dangerous levels….

He said that there is evidence of a ‘compost bomb’ around 55 million years ago that caused a huge amount of carbon to be released into the atmosphere all at once.

Scientists are also investigating whether a ‘compost bomb’ caused the peatland fires around Moscow a couple of years ago.

“We know how the compost bomb process works, we think we have seen it in the past, we just do not know what global warming will trigger it or when it will happen, ” he said….

“The further and faster we push temperatures up, the more serious the risks,” he said. “But we simply do not know where these tipping points lie.”

This point was underscored in the final statement:

The past decade has seen the emergence of important areas of new scientific understanding by which to define what we are witnessing:

A1. Humanity’s impact on the Earth system has become comparable to planetary-scale geological processes such as ice ages. Consensus is growing that we have driven the planet into a new epoch, the Anthropocene, in which many Earth-system processes and the living fabric of ecosystems are now dominated by human activities. That the Earth has experienced large-scale, abrupt changes in the past indicates that it could experience similar changes in the future. This recognition has led researchers to take the first step to identify planetary and regional thresholds and boundaries that, if crossed, could generate unacceptable environmental and social change.

I was also glad to see the statement be as clear as possible that we need to start pricing carbon pollution and valuing ecosystem services:

Recognition of the monetary and non-monetary values of public goods such as ecosystem services, education, health and global common resources such as the oceans and the atmosphere. These must be properly factored into management and decision-making frameworks at the national and sub-national levels to ensure that economic activities do not impose external costs on the global commons. Corrective measures that internalize costs and minimize the impacts on the commons need to be identified and implemented through regulatory and market-based mechanisms.

This is one more international conference by leading experts demanding “urgent and large-scale action” to protect civilization. When will policymakers and the media start listening?