The tipping points of James Hansen, climate scientist

The tipping points of James Hansen, climate scientist


Jonathan Oosterman

Thursday 28th April, 2011


Tipping points - the more we cross, the closer we get to the point of no return, where amplifying feedbacks create runaway climate change. In this possible future, the chaotic mix of rising sea levels, extreme storms, floods and droughts, would lead to ecological collapse, ultimately making our planet uninhabitable.

According to Dr James Hansen, director of NASA's Goddard Institute for Space Studies and one of the world's leading climate scientists, we are far closer to this grim scenario than the public realises. His recognition of this has pushed him to a personal tipping point, where he has decided to stand up and be more vocal about what the world is facing. He will be doing exactly this in New Zealand from May 11-21, in a series of talks on the topic ‘Human-Made Climate Change: A Scientific, Moral and Legal Issue'.

In 1988, Dr Hansen alerted a United States congressional committee to the dangers of climate change, thereby also helping bring it to the whole world's attention, but with no significant government action resulting from his efforts, he returned to his climate research.

As his recent book Storms of my grandchildren describes, in 2004 he began speaking out about climate change once again because of a sense of responsibility to his grandchildren and to the world they were inheriting.

What the science clearly shows, Dr Hansen states, is that we are in an emergency. Such an emergency requires urgent action, but this urgency isn't present in either public action or government policy. New Zealand is a case in point.

The National Party's goal of 50 per cent cuts in greenhouse gas emissions by 2050 is both far less than what is required, and undermined by putting oil and coal at the top of its energy strategy.

This demonstrates what Dr Hansen sees as the other part of the crisis we are in: greenwashing. Not only are governments all talk and no do, but the media are letting governments get away with this "fake environmentalism".

Fifty per cent cuts sound like a lot, but it's not enough, as growing knowledge of feedback mechanisms makes clear. "Feedbacks are the guts of the climate problem," Hansen writes. ‘Positive' feedbacks amplify warming just like microphone feedback amplifies sound and very quickly becomes "unbearable", he explains.

These feedbacks aren't just theoretical, they're happening now. In 2007, when the Arctic ice was found to be melting far earlier than expected, it became apparent that a major tipping point had been passed, triggering an important feedback process. Warming causes the melting of Arctic ice, which in turn causes more warming, because the sea and rocks exposed by this melting absorb heat, rather than reflect it like snow and ice.

The danger is that the warming caused by such feedbacks might lead to the collapse of the Greenland and West Antarctic ice sheets, contributing to the release of frozen methane in the permafrost and the ocean, adding additional warming as each of these processes accelerates.

What these feedback mechanisms mean is that stopping global warming at, say, two degrees Celsius above pre-industrial levels may well be a climatological impossibility. Scientists don't know exactly when the crucial tipping point might be crossed, but as Dr Hansen has said, "You do not want to reach a point where you begin to get collapse (of ice sheets) and rapid change. If you reach that point you have gone too far and it will be out of humanity's control."

Two degrees might kick off amplifying feedbacks that would bring the rise to three degrees, which in turn might take it to four, then five, then six... If ‘business-as-usual' continues, Hansen says, this continual warming wouldn't stop, at least not at any point relevant to human life on Earth.

Because of such concerns, Hansen and his colleagues have formulated a goal of 350ppm (parts per million) of carbon dioxide in the atmosphere, now well-known because of the international climate movement, founded by writer Bill McKibben, which has been very active in recent years.

Hansen suggests that this 350ppm level is a maximum, and that 300-325ppm might be necessary to stabilise ice sheets. Because the current carbon dioxide concentration is 391ppm and still rising, the world is already in the dangerous range, according to Dr Hansen, and we need to take ourselves out of it as quickly as possible if we want to avoid environmental and social collapse.

To reach the goal of 350ppm, Dr Hansen says a substantial and continually rising price on carbon emissions is needed. Just slowing down emissions is not enough, though, he says, and this can only mean one thing: most fossil fuels must be kept in the ground. All of our efforts to be green will be in vain if we burn more carbon.

In addition to this, Dr Hansen states that we also need to begin drawing down carbon dioxide out of the atmosphere, through forest preservation, massive reforestation projects and improved agricultural practices.

And when Dr Hansen talks about keeping fossil fuels in the ground, his major focus is on coal. He is willing to give some leeway for use of other fossil fuels as we transition towards more efficient practices and other energy sources, but there is no such leeway for coal.

He has called coal-fired power plants "factories of death", and referred to coal trains as "death trains". The connection between coal use and climate disaster deaths may not be intuitively obvious to everyone, but Dr Hansen wants to make it clear.

He calls for a world-wide moratorium on new coal-fired power plants, and movement to close existing plants, saying that developed countries need to completely phase out coal by about 2020, and other countries by 2030. Ultimately, this is far better than any sort of emission reduction targets, he argues.

This focus on coal is highly relevant to New Zealand. John Key's National Government supports state-owned coal company Solid Energy and its plans to invest billions of dollars in mining low-grade lignite coal in Southland. These plans include coal-to-liquid fuel and coal-to-fertiliser conversion - about the dirtiest things around when it comes to high-emission activities.

Dr Hansen's New Zealand tour includes participation in the ‘Symposium on the Future of Coal' at Victoria University in Wellington (at which Don Elder, CEO of Solid Energy will also speak), and a public meeting in Gore, near the proposed Southland lignite mines.

And so, with corporate lobbying and political greenwash undermining efforts to stop climate change, Dr Hansen argues that we desperately need to take action ourselves.

He began his own path of action by becoming explicit about the policy implications of his scientific work, by writing newspaper articles and open letters, and by actively seeking opportunities to speak to government leaders around the world. He was moved to study Gandhi's concepts of civil resistance. He has testified in the defence of coal activists. And the 70 year-old Dr Hansen has himself been arrested more than once for his involvement in protests against coal mining.

James Hansen reached his own tipping point and began to speak out and act. He is part of the growing global community which is taking the climate emergency seriously, giving inspiration and hope in the struggle for a safe and stable climate. Above all, though, Dr Hansen shows that if we are to have any hope of retaining a liveable planet, it is absolutely necessary that we reach our own tipping points towards change before the climate does.


Dr Hansen's speaking tour

Thursday 12th May, Auckland - 6pm, University of Auckland Business School OGGB4, Level 0, Owen Glenn Building, 12 Grafton Road

Friday 13th May, Palmerston North - 1:30-2:45pm, Japan Lecture Theatre, Massey University

Saturday 14th May, Radio - 8:15am, Radio NZ with Kim Hill

Monday 16th May, Wellington - 5:45pm, Rutherford House

Tuesday 17th May, Wellington - 10:20-11:30, on panel 4-5:30pm, ‘Symposium on the Future of Coal', Victoria University

Wednesday 18th May, Dunedin - 5:30-7pm, St David's Lecture Hall

Thursday 19th May, Gore - 2pm, Gore District Council Building

Friday 20th May, Christchurch - 12-1pm, University of Canterbury

Friday 20th May, Christchurch - 5:30pm, Canterbury Horticultural Centre, 57 Riccarton Avenue (in Hagley Park)

Saturday 21st May, Auckland - 2:30pm, Town Hall (as part of ‘Festival for the Planet')


Attributions for photos are as follows:

James Hansen (head) - Jiri Rezak/Greenpeace
Dr Hansen protesting (at anti-coal rally at the Capitol in Washington DC, 2009)- Kate Davison/Greenpeace
James Hansen and family (wife, daughter and grandchildren) - Matthew Harnick