worse than we thought – glaciers in Greenland!

The study—written by James Hansen, NASA’s former lead climate scientist, and 16 co-authors, many of whom are considered among the top in their fields—concludes that glaciers in Greenland and Antarctica will melt 10 times faster than previous consensus estimates, resulting in sea level rise of at least 10 feet in as little as 50 years.

The implications are mindboggling: In the study’s likely scenario, New York City—and every other coastal city on the planet—may only have a few more decades of habitability left. That dire prediction, in Hansen’s view, requires “emergency cooperation among nations.”

The Slate, 20 Jul 2015

keep off the grass!

In Australia, where 11 million cattle range in Queensland alone, this call for livestock reform has been a whisper on the edges of the greenhouse debate. I became interested after reading a letter by animal rights activist Geoff Russell to climate-change campaigner Tim Flannery.

In his letter, Russell quotes climate scientist James Hansen, who says meat reduction is the second-most important thing one can do to combat climate change (the most important is to elect a government committed to action). Russell then quotes the CSIRO, who “have tested Australian cattle on grass and grain – those on grass produce about three times more methane”.

Could this be true? Could a fat corn-fed cow be better for the environment than one allowed to range over grass?

Sydney Morning Herald, 17 Feb 2009

stable shoreline slips away

“More ominous tipping points loom. West Antarctic and Greenland ice sheets are vulnerable to even small additional warming. These two-mile-thick behemoths respond slowly at first, but if disintegration gets well under way, it will become unstoppable. Debate among scientists is only about how much sea level would rise by a given date.

In my opinion, if emissions follow a business-as-usual scenario, sea level rise of at least two meters is likely within a century. Hundreds of millions of people would become refugees, and no stable shoreline would be reestablished in any time frame that humanity can conceive.”
Dr James Hansen, Twenty Years Later: Tipping Points Near on Global Warming, Huffington Post, 07/01/2008 , Updated May 25, 2011

Saved, but the party’s still over

“According to climate scientist James Hansen, we are never going to see another ice age, ever. When the ice melts it will not be replaced. Ice extent will fluctuate from year to year, and some climate change deniers will selectively point to recovery years, but there is only a downward escalator. Which means, unless dangerous climate change is addressed, for some of us today, and many more tomorrow, the party will definitely be over.”The Conversation, 20 Sep 2013

tipping point passed

“Today I testified to Congress about global warming, 20 years after my June 23, 1988 testimony, which alerted the public that global warming was underway. There are striking similarities between then and now, but one big difference. The difference is that now we have used up all slack in the schedule for actions needed to defuse the global warming time bomb.

The next president and Congress must define a course next year in which the United States exerts leadership commensurate with our responsibility for the present dangerous situation.

Otherwise it will become impractical to constrain atmospheric carbon dioxide, the greenhouse gas produced in burning fossil fuels, to a level that prevents the climate system from passing tipping points that lead to disastrous climate changes that spiral dynamically out of humanity’s control.”

Dr James Hansen, Twenty Years Later: Tipping Points Near on Global Warming, Huffington Post, 07/01/2008 , Updated May 25, 2011

uninhabitable planet!

uninhabited_planetThe world is currently on course to exploit all its remaining fossil fuel resources, a prospect that would produce a “different, practically uninhabitable planet” by triggering a “low-end runaway greenhouse effect.”

This is the conclusion of a new scientific paper by Prof James Hansen, the former head of NASA’s Goddard Institute for Space Studies and the world’s best known climate scientist.
The Guardian, 10 Jul 2013

Great flying boulders!

flying_boulderAnother danger of climate change: Giant flying boulders?

The idea is that Earth’s climate went through a warming period just over 100,000 years ago that was similar in many ways to the warming now attributed to the actions of man.

And the changes during that period were so catastrophic, they spawned massively powerful superstorms, causing violent ocean waves that simply lifted the boulders from below and deposited them atop this cliff.

If this is true, the effort kicking off in Paris this week to hold the world’s nations to strict climate targets may be even more urgent than most people realize.
Washington Post, 28 Nov 2015, article on James Hansen’s theory about giant flying boulders

thanks to ddh

Doomsday – 2016

There is a growing fear among scientists that, thanks to man-made climate change, we are about to return to a world of climatic turbulence, where tipping points are constantly crossed. Their research into the workings of the planet’s ecosystems suggests why such sudden changes have happened in the past, and are likely again in future. Soon it could be a great deal more.

Jim Hansen of NASA, George Bush’s top climate modeller, predicts sea-level rise will be 10 times faster within a few years, as Greenland destabilises. “Building an ice sheet takes a long time,” he says. “But destroying it can be explosively rapid.” Hansen says we have 10 years to turn things around and escape disaster.
Sydney Morning Herald, 11 Nov 2006

Doomsday – 2012

Barack Obama has only four years to save the world. That is the stark assessment of Nasa scientist and leading climate expert Jim Hansen who last week warned only urgent action by the new president could halt the devastating climate change that now threatens Earth. Crucially, that action will have to be taken within Obama’s first administration, he added.
The Guardian, 18 Jan 2009

see also – Doomsday

250 feet (76 meters)

Despite uncertainties in reserve sizes, it is clear that if we burn all the fossil fuels, or even half of the remaining reserves, we will send the planet toward an ice-free state with sea level about 250 feet higher than today. It would take time for complete ice sheet disintegration to occur, but a chaotic situation would be created with changes occurring out of control of future generations.
James Hansen in Inside Climate News, 15 Jul 2009

82 feet (25 metres)

“The last time the world was three degrees warmer than today – which is what we expect later this century – sea levels were 25m higher. So that is what we can look forward to if we don’t act soon. None of the current climate and ice models predict this. But I prefer the evidence from the Earth’s history and my own eyes. I think sea-level rise is going to be the big issue soon, more even than warming itself.”
Jim Hansen, “Climate change: On the edge” The Independent, 17th February, 2006