Tag Archives: temperature stabilisation

Climate action: a doddle or deep adaptation?

Again, this post started as an edition of Climate clippings.

Where I ended up after a series of happenings as described below, is concluding that we need a paradigm shift in our climate change aspirations. Instead of trying to limit warming to a point where we can avoid dangerous climate change, we need to recognize that we’ve already gone too far, that the climate is already dangerous, so we should aim to ratchet down GHG concentrations in the atmosphere to attain a safe climate.

1. Germans look to 7.4 trillion tons of fake snow to save the West Antarctic Ice Sheet

Continue reading Climate action: a doddle or deep adaptation?

Saudis throw a spanner

Climate science was buried at a meeting in Bonn. Meanwhile diplomats planted trees to symbolise their intention to combat desertification (Photo: UNFCCC)

At a mid-year meeting of UNFCCC in Bonn this year in June a small group of countries led by Saudi Arabia have put the kybosh on any formal consideration of the IPCC Special Report on 1.5°C in the UNFCCC forum. Continue reading Saudis throw a spanner

IPCC on 1.5°C: the target is wrong, but we have a strong wake-up call

The target should not be 1.5°C; rather we should aim for a safe climate. James Hansen told us in 2007 that to achieve a safe climate we need to bring GHG concentrations down to 350 ppm as soon as possible. That’s CO2 equivalent, not CO2. Current CO2e is not often quoted, but would be around 500 ppm on the basis that CO2 is about 80% of total GHGs. Also we need to focus on what we are doing to the planet over centuries and millennia, not just the next 50 to 100 years.

However, the IPCC team putting the report together were not asked what the goal should be. They were asked to build a scenario for achieving the 1.5°C warming limit specified as desirable in the Paris Agreement of 2015, and to look at the impacts of a 1.5°C world as against a 2°C world. Two Degrees came out of Europe in the 1990s, achieved a general currency, then became the official goal of at the Conference of Parties of the UNFCCC in Cancun in 2010. At that time there was a move mainly by many of the island states vulnerable it inundation for a more ambitious target. Essentially the whole group at Paris agreed to try.

However, while two degrees was commonly seen as a guardrail for a safe climate even by many scientist, it was never a scientifically derived goal for a safe climate.

The IPCC Special Report on 1.5°C is important because it shows that the path to 1.5°C has a high degree of difficulty and has implications which to most will not be acceptable. It’s importance is in changing the discourse, from being seen as an achievable safe guardrail to 1.5°C as difficult to achieve and far from safe. Continue reading IPCC on 1.5°C: the target is wrong, but we have a strong wake-up call

Science shows the need for urgent climate action

In August last year in Climate clippings 181 (Item 5) I linked to a report by Climate Analytics examining the impacts on Australia of limiting global temperature rise to 1.5°C and 2°C.

For me the crux of the report is this, from a discussion piece at The Conversation:

    The report predicts that half of the world’s identified tipping points – such as the collapse of polar ice sheets and the drying out of the Amazon rainforest – would be crossed under 2C warming, compared with 20% of them at 1.5℃.

If we go to 2℃, we will have a very different climate and there is a good chance we won’t be able to stabilise there. The bad news is that if we just carry on we’ll reach 1.5C by 2024, and 2C by 2036. Continue reading Science shows the need for urgent climate action

Hansen’s new temperature graph heads north

James Hansen and Makiko Sato have just released a new temperature graph, which highlights the underlying trend, and is more than a little alarming:

hansen_temperature_cropped_600

See also his blog post that looks at the implications and what we need to do. Continue reading Hansen’s new temperature graph heads north

Saving the planet

At the Paris climate conference a surprise result was for the world to aim to hold “the increase in … temperature to well below 2°C … and to pursue efforts to limit the temperature increase to 1.5°C”.

Fred Pearce in the New Scientist now takes a look at what some are saying needs to be done. Continue reading Saving the planet

Climate clippings 153

1. July hottest ever

Not just the hottest July, we’ve just had the hottest single month since records began in 1880. It’s also been the hottest first seven months of any year, so we are heading into new territory. Continue reading Climate clippings 153

Is 1.5°C attainable?

With increasing appreciation that limiting global temperature rises to 2°C amounts to folly, is 1.5°C attainable? Is 2°C the best remaining scenario on offer?

For the Bonn UNFCCC climate talks in June a report was presented from 70 scientists gathered together in a process called the “structured expert dialogue”. It warned that even current levels of global warming of around 0.85°C are already intolerable in some parts of the world: Continue reading Is 1.5°C attainable?

Two degrees

Carbon Brief has compiled a series of three posts on the so-called 2°C ‘guardrail’ used in global warming discourse:

This post will pick out some of the highlights, but is not a substitute for reading the posts. Continue reading Two degrees

The folly of two degrees

Back in 2011 David Spratt took a look at where we were in relation to temperature rise and the Holocene. At 2000 we were at 0.7°C above the pre-industrial temperature. This happens to coincide with the Holocene maximum:

Holocene_thin-blue-line 600

Spratt says James Hansen warns that at 0.7°C the ice sheets start to become unstable, so in terms of sea level rise alone we are entering a danger zone. Since then the temperature has risen ~ 0.15°C.

From this point of view the 2°C guardrail looks hazardous in the extreme. Continue reading The folly of two degrees

Assessing dangerous climate change

Seventeen high-profile academics with expertise across the climate research spectrum, from atmospheric science, earth science and environmental science, to economics, global change and public health led by James Hansen, now at Columbia University’s Earth Institute, have published a paper Assessing “Dangerous Climate Change”: Required Reduction of Carbon Emissions to Protect Young People, Future Generations and Nature which demands attention.

The bottom line is that “aiming for the 2°C pathway would be foolhardy” because it “would have consequences that can be described as disastrous”. The authors believe that humanity and nature, the modern world as we know it, is adapted to the Holocene climate that has existed more than 10,000 years. Departing from this climate by more than 1°C would have intrinsically harmful effects. At 2°C these effects become unacceptably severe. Moreover we enter a zone where further feedbacks, such as ice sheet response, methane release and vegetation change, are likely to push the climate towards further warming, of probably at least 3°C.

James Hansen and Pushker Kharecha have done a summary with discussion here, then there’s Joe Romm at Climate Progress, Tim Radford at Climate Code Red, Damian Pattinson, Editorial Director, PLOS ONE, at Huff Post and John Rennie with links to further material at PLOS Blogs. My partial summary is below. Continue reading Assessing dangerous climate change