Climate Change Close to Tipping Point, Soon Irreversible

Scientists keep beating the drum, hoping the world will wake up to the fact that climate change is a real, non-partisan, non-advanced vs development country issue.

At the Planet Under Pressure Conference, taking place in London, 2800 scientists warn the earth is dangerously close to an irreversible tipping point.

Dubbing the phenomenal recent explosion in human activity, "The Great Acceleration," leading scientists say time is running out to minimize the risk of setting in motion irreversible and long-term climate change and other dramatic changes to Earth’s life support system.

If nothing is done, the world is on track for the worst predictions with temperatures set to rise by 6 degrees Celsius by 2100.

"This is the critical decade. If we don’t get the curves turned around this decade we will cross those lines," says Professor Will Steffen, executive director of the Australian National University’s climate change institute.

The tipping point has likely been passed for the world’s glaciers and polar ice caps and as the planet warms we’ll lose the Amazon rainforest. It is already getting drier, killing off the trees, and adding to emissons rather than absorbing them.

Even more worrying is the potential for the Siberian permafrost to thaw, which holds about twice the carbon as is in the atmosphere right now. The most severe temperature changes are occuring in the northern high latitudes, making this nightmare scenario possible.

So much carbon is being emitted that the oceans are saturated with it – they can’t absorb more and are becoming acidic at a rate not seen for 60 million years. That is killing off the world’s coral reefs and any sea creature that needs to develop a shell.

"The last 50 years have without doubt seen the most rapid transformation of the human relationship with the natural world in history," says Professor Steffen.

"Many human activities reached take-off points sometime in the 20th Century and sharply accelerated towards the end of the century. It is the scale and speed of the Great Acceleration that is truly remarkable. This has largely happened within one human lifetime."

Key indicators of the planet’s state are: higher levels of carbon dioxide in the atmosphere, phosphorus extraction and fertilizer production causing huge dead zones in coastal areas; rising air and ocean temperatures; melting sea ice, polar ice sheets and Arctic permafrost; rising sea levels and ocean acidification; biodiversity loss; land use changes; and growing consumption of freshwater supplies and energy by swelling numbers of people worldwide, even as billions of people lack even the most basic elements of well-being.

At a planetary level, humanity is altering the global carbon cycle, water cycle and nitrogen cycle, says Steffen.

Some Positive Signs

"There are signs that some drivers of global change are slowing or changing," says Professor Diana Liverman, co-Director of the Institute of the Environment at the University of Arizona.

"Population growth is slowing and will level off; the intensity of energy and carbon required for a unit of production is declining; agricultural intensification is slowing and forests are starting to expand in some regions."

"On the other hand, average resource consumption per person, already high in some regions, is growing steeply in emerging economies even as many poor people cannot meet basic human needs. We have a long way to go to turn things around."

She notes the Earth has entered a new geological epoch hallmarked by the profound ecosystem impacts of one species – humans – so much so that it marks an entirely new geological timespan: the "Anthropocene."

"In countries with high income inequality, the richest 10% of the population may be responsible for more than 50% of the greenhouse gas emissions – and the growing middle classes of many developing or transitional countries are developing consumption habits that add to the burden on the earth system."

"Our presenters today are akin to doctors saying ‘look, you may not feel too sick at the moment but you’ve got high blood pressure, your cholesterol is going up, and your lifestyle is not conducive to good health," says Dr Lidia Brito, science-policy director of UNESCO.

The conference is the largest gathering of experts in global sustainability in advance of June’s United Nation’s "Rio+20" summit in Brazil and the largest gathering ever of such a group of experts.

Check out the conference and listen to the web streams: