Tag Archives: Tripati_Aradhna

Climate clippings 125

1. Paris climate talks won’t keep warming below the dangerous 2°C Limit

Joe Romm at Climate Progress believes the Paris climate talks should not be written off as a failure if they don’t do enough to keep warming below 2°C. He thinks the CFC ozone layer example is apt. The Montreal Protocol was concluded in 1987. Initially the protocol’s targets and timetables slowed the rate of growth of concentrations only slightly and would have still led to millions of extra cases of skin cancer by mid-century.

President Reagan endorsed the protocol, and the Senate ratified it. By the end of 1988, 29 countries and the European Economic Community — but not China or India — had ratified it. The treaty came into effect the next year. But it took many more years of negotiations, continuous strengthening of the scientific consensus, and significant concessions to developing countries before amendments to the treaty were strong enough and had enough support from both rich and poor countries to ensure that CFC concentrations in the air would be reduced.

Elsewhere 14 high-profile CEOs want to decarbonise the economy completely by 2050. They are the B Team led by Virgin founder Richard Branson. See also at The Guardian.

2. 2013 record heatwave ‘virtually impossible’ without climate change

That’s according to a new report from the Climate Council.

From The Guardian:

The country experienced its hottest day, month, season and calendar year in 2013, registering a mean temperature 1.2C above the 1961-90 average.

The Climate Council says recent studies show those heat events would have occurred only once every 12,300 years without greenhouse gas emissions from human activities.

Record hot days have doubled in Australia over the past 50 years. During the past decade heat weather records were set three times more often than cold ones.

Heatwaves across Australia are becoming hotter, lasting longer, occurring more often and starting earlier.

The ABC article has handy links to other sites.

The following graph shows the number of days each year where the Australian area-averaged daily mean temperature was above the 99th percentile for the period 1910-2013:

Hot days Australia_cropped_600

3. Two degrees by 2036

Michael Mann using an Earth energy balance model has calculated that we could reach 2°C of warming as early as 2036. To stay within the 2°C guardrail we need to limit CO2 concentrations to 405 ppm. It would be 450 ppm but for the aerosol issue. If we cease burning coal we lose the cooling effect of the crap that coal spews into the atmosphere along with CO2.

Mann has done the calculation on the basis of climate sensitivity of 3°C. Problem is, he says, that this modelling is based only on short term feedbacks.

David Spratt at Climate Code Red has done a long and thorough post based on Mann’s article. Spratt looks in some detail at the longer term climate sensitivity issue, drawing also on the work of James Hansen, Aradhna Tripati and others. Hansen found that climate sensitivity with long term feedbacks was considerably higher than 3°C; Tripati found that in the Miocene with CO2 concentrations similar to now “temperatures were ~3° to 6°C warmer and sea level was 25 to 40 meters higher than at present”.

Spratt also reminds us that 2°C warming is not safe.

4. Would turfing Abbott help climate change policy?

In short, yes, but perhaps not a lot. The conservative side of politics is still infested with climate change denialists.

Mother Jones in an article One of the World’s Worst Climate Villains Could Soon Be Booted From Office would clearly like to see the back of Abbott. Julie Bishop has a background of denialism, but is pragmatic and has understood from the Lima experience that our stance on climate is negatively affecting our international standing.

Turnbull stated back in 2009:

“I will not lead a party that is not as committed to effective action on climate change as I am.”

He would now, of course.

Tristan Edis looks at actions Turnbull might get away with. Giles Parkinson thinks he might rescue renewable energy and could adapt Direct Action into a baseline and credit scheme.

See also Lenore Taylor at The Guardian.

Climate clippings 118

1. Growth in CO2 slows

Global carbon dioxide (CO2) emissions from fossil fuel use and cement production grew 2% in 2013 to the new record of 35.3 billion tonnes of CO2. This was about half the average for the last 10 years and less than global GDP growth of 3.1%.

2. Aradhna Tripati gets a gong

The Center for Biological Diversity presented its third annual E.O. Wilson Award for Outstanding Science in Biodiversity Conservation to Dr. Aradhna Tripati for her groundbreaking research on carbon dioxide’s role in climate change.

Tripati’s work revealed that the last time CO2 levels were as high as they are today was 15 million to 20 million years ago, when the distribution of plants and animals was dramatically different, global temperatures were 5 to 10 degrees warmer, and the sea level was 75 to 120 feet higher than today. Her research suggests that the CO2 threshold for maintaining year-round Arctic ice may be well below modern levels.

Converting from Fahrenheit to Celsius and feet to metres that would make 2.7 to 5.5°C and 23 to 36 metres.

I would caution that the shape of the ocean basins may have been different, but these are alarming findings.

3. 1000-year drought history of Queensland and New South Wales

By analysing ice cores Australian scientist have found that there were eight droughts in the last millennium that lasted more than five years, with one of the so-called mega droughts lasting for almost 40 years. That was back in the 12th century.

This tends to indicate that the Millennium Drought and the Big Dry from 1997 to 2009 were not unusual.

From the official news release:

Explaining the findings, Dr Vance said the ice core analysis had significantly enhanced our understanding of a relatively poorly understood phenomenon known as the Interdecadal Pacific Oscillation (IPO).

The IPO describes a roughly 25-year cycle in the sea surface temperature, wind and other factors in the Pacific Ocean.

The IPO’s positive phase is closely linked with longer and more severe droughts in the United States and Australia. The risk of droughts occurring in Australia is higher during the IPO’s positive phase.

I’m not questioning the findings but how drought in Queensland and NSW can be derived from drilling ice cores in the Antarctic is not immediately obvious.

Where does this leaves global warming? The authors don’t say, but the clear implication is that severe droughts are part of the natural cycle. Warming is a given. The most recent analysis I recall is that drying along the southern edge of the continent has a climate change component. North of the Victorian border there is uncertainty.

4. Lifters or leaners?

Or backmarkers. UK PM David Cameron thinks Australia does not want to be a “backmarker” on climate change action. Global pressure will make us do more. Has he met our Tones?

Christian Downie thinks the real achievement of the Lima climate talks

wasn’t the goals set, but the fact that international talks like these make it increasingly hard for breakaway countries to ignore the issue.

John Kerry spells it out:

“If you are a big developed nation and you do not lead, you are part of the problem.”

Part of the problem indeed, and perhaps an active climate change vandal. Kieran Cooke reports that in Lima Australia was “lobbying for rules that undermine the integrity of the emissions accounting system”.

5. Antarctic sea ice

One of the conundrums of climate science has been the question of why the Antarctic sea ice has been expanding. Eric Steig at RealClimate takes a detailed look. One of the complexities is that the sea ice is expanding in some places and contracting in others. This, he says, rules out simplistic notions like an increase in westerly winds.

However, if you take into account the changes in all the wind patterns in the Antarctic you get a better match, indeed a good match.

Finally Steig says:

Not incidentally, changing winds also have a lot to do with what’s been happening to the Antarctic ice sheet (meaning the land-based glaciers, distinct from the sea ice). I’ll have another post on that later this month, or in the New Year.