22/05/2016

Why We Must ‘Think Global, Act Local’ On Climate Change

Renew Economy

Many catchy slogans come and go: "Just do it", "Carpe Diem", "play hard." But out of all of them, "think global, act local" is the one that resonates the most with me, and seems to apply best in this age when we are all connected but still have individual responsibilities.
It's a slogan that's become more and more applicable in an era of distributed energy when every consumer that wants to, can make a difference at the local level. Disruptive technology typically depends on many individuals making small individual decisions that collectively have large impacts on corporate behaviour. In that spirit and as part of the "cognitive surplus" its seems worthwhile to pull together three articles that summarise some well known, and some slightly less well known, features of the global context that underlies the unfolding energy transformation in Australia.
Article 1 today is a very brief and familiar summary of the global warming data and the primary contributors to CO2 emissions.
Article 2 will summarise the global renewable energy picture; and Article 3 will look at some of the recent global data and analysis, including China and India coal-fired electricity generation and economics.

Global temperature
I prefer to look at the global temperature in percentage terms. That's because, in my experience, 1 degree doesn't sound like something very important to the man in street, who is used to daily fluctuations of 10 degrees or more. Using percentages has its own problems, as Centigrade percentages will differ from Fahrenheit and, for the truly obsessed, Kelvin scales. Our primary data source is the National Oceanic and Atmospheric Administration (NOAA) and we like to use a 20-year moving average as the most smoothed form of data.
The disadvantage of moving averages is that they are out of date and give equal weight to old observations. This can be seen in the chart below. For that reason the ABS uses a "Henderson" trend for monthly and quarterly data, which gives more weight to the current observations and less weight to the older observations. Any stats-inclined people out there who want to calculate a 20-year Henderson weight, please get in touch. Here's the chart then. The anomaly average for calendar 2016 year to date is 1.13°C, about 8 per cent above the 20th century average.

Carbon emissions
The assumptions that underlie our thinking are:
The climate sensitivity is 3. That is, a doubling of CO2 concentration would lead to a 3°C temperature change. This relationship is linear, and emissions stay in the atmosphere for thousands of years.
  • The current concentration is 397 ppm of CO2.
  •  To keep temperature change at 2°C relative to the 20th century average of just under 14°C, cumulative emissions need to peak at around 800 GT of carbon. 1GT of carbon = 3.66 GT of CO2.
  • Cumulative carbon emissions at the end of 2015 are estimated at 550-600GT, an increase of about 11 GT YoY.
  • At the current rate, 800 GT will bet reached in 2035.
The following chart shows the cumulative causes from 1870 to 2014 of the increase in CO2.

From an economic perspective, electricity production is the No 1 cause of carbon emissions following by agriculture and industry.
global 3
And this chart shows that in recent years the increase in coal consumption is the main factor impacting the rate of change in carbon emissions.
 Looking at emissions by geography, the impact of China – and to a lesser extent, India – is clear, but the chart also shows that the collective rest-of-world, including Russia and Eastern Europe, Africa and South America and the remainder of Asia, continues to show significant growth. Cumulative emissions show that China is rapidly catching Europe and even India can no longer reasonably state that they didn't cause the problem, therefore they don't have to worry.
global 5
It's no great secret that the increase in coal is largely due to the growth of Chinese manufacturing. One view is that China has done the world's "metal and chemical bashing" in the past decade and, as such, China is just a symptom of the global problem.
Even so, we can see that limiting future coal and oil use in China and India, and limiting global oil consumption, are the two main drivers of slowing down the rate of increase in global temperatures.
The global carbon budget, simply put, shows that limiting total human-induced warming (accounting for both CO2 and other human influences on climate) to less than 2°C relative to the period 1861–1880 with a probability of 66 per cent would require total CO2 emissions from all anthropogenic sources since 1870 to be limited to about 2900 GtCO2. That's about 790 GtC. Recent emission rates are about 9.8 GtC per year and at that rate 2°C will be locked in by the mid 2030s.

At this point, any number of scenarios can be constructed about the rate of change and we will return to them over the next couple of articles. We close with the fact that, even based on the oil price (not the petrol or diesel price), the global oil industry has revenue of about $US1.7 trillion per year and the global coal industry about $US0.4 trillion. Gas and cement and land use loss of GDP from the efforts to reduce CO2 emissions are certainly not trivial. Annual emissions have basically been growing and are closely tied to GDP. In short the challenges facing the world and renewable energy industry shouldn't be underestimated.


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Australian Scientists Warn Of Climate Change Flash Flood Risk In Cities

Independent Australia - Tim Radford

Scientists in Australia warn that global warming will lead to more intense and concentrated summer storms seriously testing city drainage systems already struggling to cope.
Australians have already seen the devastating impact of floods in our cities (Image screenshot from YouTube video below)
CLIMATE CHANGE could bring the equivalent of the flash flood to the modern city. That is because, as global temperatures rise, summer storms will deposit more moisture.
Australian scientists say peak rainfall will also be more intense, over a more confined area and over a shorter timespan. And when overwhelming levels of rain fall on asphalt, tiles and cement, drainage systems built for a different climate regime may fail to cope.
"As warming proceeds, storms are shrinking in space and time," said Conrad Wasko, a PhD candidate in the school of civil and environmental engineering at the University of New South Wales (UNSW).
He continued:
"They are becoming more concentrated over a smaller area, and the rainfall is coming down more plentifully and with more intensity over a shorter period of time. When the storm shrinks to that extent, you have a huge amount of rain coming down over a smaller area."


Total precipitation

Most climate predictions are based on computer simulations that extend existing data. But this study is based on storms that have already happened.
Wasko and his colleagues report in Geophysical Research Letters that they analysed data from 1,300 rain gauges and 1,700 temperature stations across Australia to look for a link in the local temperature to the total precipitation, duration and area of a cloudburst.
The meteorologist's rule of thumb is that the potential moisture content of the atmosphere increases by 7 per cent with every 1°C temperature rise, so it follows that summer storms should potentially deliver more rainfall. The same scientists last year established that storms were getting briefer in duration.
The latest study looked at the area of rainfall and found that the heaviest downpour had moved nearer to the centre of each storm. And although the testing ground was confined to Australia, the study could have a message for city planners and hydraulic engineers worldwide.
Professor Ashish Sharma, one of the co-authors of the UNSW study, said:
Australia is a continent that spans almost all the climate zones in the world – Mediterranean, tropical, temperate, subtropical – everything except the Arctic or Antarctic. So the results hold a lot of value. We are finding the pattern repeating itself over and over, happening around Australia and around the world.
Look at the incidence of flooding in Mumbai or in Bangkok last year — you see urban streets full of water. You see it now in Jakarta and Rome and many parts of Canada. That's because the stormwater infrastructure cannot handle the rain and part of the reason there's more rain is the increase in global temperatures.
Kuala Lumpur flash floods due to inefficient drainage system. New Straits Times
Measurable difference
In addition to record temperatures during heatwaves, Australia has been hit by devastating floods linked to climate change, and in 2010 so much rain fell on the continent that it made a measurable difference to sea levels.
The Australian authors had already predicted that floods in some places – especially the warmer urban areas – could increase by 40 per cent. But there are a number of uncertainties.
Professor Sharma said.
When we say that the storms are shrinking in space and shrinking in time, and we say floods will increase, we are making an assumption that the volume of water coming down is not changing.
That assumption is very conservative, because you would expect the air to hold more moisture. If you factor in that as well, there'll be even more rainfall and more floods.


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