These posts are intended to share information and ideas about climate change and hence act as an open thread. This post has emphasised science, observations and impacts. Comments, about science, observations impacts, and future predictions are welcome. I do not, however, want a rehash of whether human activity causes climate change.
1. SAM and ENSO divorce
Roger Jones at Understanding Climate Risk has a post on global warming breaking the link between SAM and ENSO, with consequences for our weather.
To help, GMT in the graph means ‘global mean temperature’.
With the global warming signal taken out (top panel), the relationship between ENSO and SAM is strong but with it in, they depart in the late 1960s (lower panel).
There’s also an article in The Age.
So what does this mean for Australia’s climate? It means that an overwhelmingly positive SAM is keeping the westerlies south and contributing to our drier autumn winters and delivering weather typical of the Riverina to southern Victoria according to Cai. Recovery of the ozone layer and reduction in greenhouse gas emission would stabilise this process, rather than continuing to send it south.
In summer it also allows the easterly trades greater access, bringing in more moisture from the tropics and enhancing La Niña summer rainfall.
2. Climate Commission warning
The Climate Commission has just released its report The Critical Decade 2013. It repeats what we already know: globally we can only release 1000 billion tonnes of CO2 between 2000 and 2050 to have a 75% chance of the temperature rising by 2°C. So far we’ve run through 40% of that budget, so in the next 37 years we have only 60% of that budget available. Consequently global emissions need to peak by 2020 and 80% of fossil fuel reserves need to be left in the ground.
The ABC picked up on that last point.
Our major parties say that’s well and good, but there are no implications for our coal export industry.
As to Christine Milne, no need for me to tell you what she thinks!
3. National food plan
A National Food Plan White Paper was released last month. I’ve only had time for a quick skim, but it paints a rosy picture – we are going to grow more (30% more by 2025), manufacture more and export more food (45% more) in the future.
Rebecca Lindberg and Mark Lawrence at the Conversation say more attention should have been paid to the 8% or 2 million Australians who are food deprived or food insecure.
Andrew Longmire, research fellow with Beyond Zero Emissions, says the plan essentially ignores climate change. Agriculture is responsible for 16% of our emissions. These need to be minimised, we need to look to agriculture to store more carbon and account needs to be taken of the effect of climate change on landscapes and food productivity.
HM Opposition reckon the plan’s a con job. They are going to knock off many of the 20,900 regulations introduced by the Labor Government (it has been busy!)
The NFF and other industry groups welcome the emphasis on Asia. Radio National’s PM has more, not all of it positive. Ausveg wants more action on dumping by other countries. The Opposition are going to change the onus of proof on that one. Have they heard of the World Trade Organisation which makes the rules?
4. Cheap food is a thing of the past
That’s according to a report from the OECD and FAO reported by Climate Progress:
The report cited several reasons for rising prices, including: increased demand for food and biofuels as a result of a growing population and higher incomes and standards of living, slower growth in food production, and rising energy costs.
Limited water resources and farmland availability, as well as price hikes on necessities such as fertilizer, are expected to slow the increase in food production worldwide from 2.1 percent last decade (2003 – 2012) to 1.5 percent in the next decade. Meat, fish and biofuel prices are expected to rise more than fruit, vegetables and grains, but meat production is still expected to continue to expand, with China becoming the world’s largest consumer of pork by 2022.
The report notes that “increasing environmental pressures” — which include climate change-fueled storms, drought and flooding — will be one of the main factors slowing the growth of food production around the world.
Here’s a graph of price increases in developing countries:
5. World Bank does climate change
From RN’s RN’s The World Today the World Bank has issued a dire warning about the impact of climate change on the world’s poor.
In its revised Turn Down the Heat report, the World Bank says severe hardships will be felt within a generation and it says there’s a growing chance that warming will reach or exceed four degrees Celsius in this century.
From the Executive Summary:
It finds many significant climate and development impacts are already being felt in some regions, and in some cases multiple threats of increasing extreme heat waves, sea-level rise, more severe storms, droughts and floods are expected to have further severe negative implications for the poorest. Climate-related extreme events could push households below the poverty trap threshold. High temperature extremes appear likely to affect yields of rice, wheat, maize and other important crops, adversely affecting food security.
Here’s the projected impact of climate change on the annual Aridity Index in Sub-Saharan Africa:
The left panel is 2°C and the right 4°C. In the unhatched areas 80% of the models agree, in the hatched areas 40% disagree.
6. Arctic ice
Since we’ve just passed the longest day of the year in the Arctic I thought I’d check out the sea ice extent. Go here and click on the interactive graph on the right. I’d recommend clicking on 2005, 2007, 2012 and 2013. So far this year the ice cover is persisting. In fact they’ve just had a cyclone that persisted for 25 days. As this post says it has been thought that:
fewer cyclones over the central Arctic Ocean during the months of May, June, and July appear to favor a low sea ice area at the end of the melt season.
So cyclones early in the season may preserve ice cover.
Last year there was a monster cyclone in early August which is thought to have contributed to the record melt in September.
It is possible there will be more cyclones and these will provide a negative feedback to slow the trend of ice cover loss. There is a lot going on, however, and with the ice thinning they really don’t know what the impact is going to be short or long term.
7. Global warming photos