Green Up Moggill

Watch this space for brief reviews of science topics and pointers to places where you can find out more.

If the World is Warming, How can we have very cold weather?
Global warming refers to the long-term world-wide average. Redistribution of energy from one part of the planet to another may make some areas warmer and others cooler. For example, in the northern hemisphere 2009-2010 winter, some areas experienced extreme cold. However, if you look at the distribution of northern hemisphere temperatures, what happened was that the Arctic warmed considerably. Look at the image: the Arctic region shows strong warming, with Greenland considerably warmer than usual (more accurately, less chilly), yet Northern Europe and North America are large local areas of cooling. Possibly this effect caused cold air to move south, but in any case, the cooler overall northern hemisphere in the most inhabited regions has hit the news, a slightly misleading picture when you look at the whole map.

Dead Zones
A dead zone is part of the ocean where oxygen levels are too low (less than 2 parts per million) to support life, or anoxic. Here is a site at Montana State University that provides some information. For more, see NASA’s information on dead zones. Algal blooms can make part of an ocean anoxic. In an extreme case, about 251-million years ago, the oceans became widely anoxic, as part of a mass extinction event at the boundary between the Permian and Triassic though probably that event had different causes.

Life In Your Back Yard
Want to find out if there are endangered species or unwanted alien invaders somewhere, or just check out who or what your wild neighbours are? The federal environment department has a great tool for finding these things out. Click the “Interactive Map“ link, find your area of interest on the map, click Report and use the mouse to drag out a rectangle on the map.

How Green is the electric car?
Electric cars – in the early days of motoring, a mainstream option – are making a comeback, with variations such as hybrids and plug-in hybrids. But how green are they really? Here’s an article with more detail. Check out Tesla’s first sedan. A UK company, Riversimple, has some interesting ideas on how to build an ultra-efficient car using a hydrogen fuel cell. I remain unconvinced of the hydrogen economy because hydrogen takes a lot of energy to produce, but Riversimple has some interesting ideas, like leasing the cars rather than selling them as a way of avoiding the false economy of planned obsolescence.

Smart Grid
Something that will be talked about increasingly is managing energy use more intelligently not only to be more efficient but to fit swings in demand to swings in supply better, as a remedy for the intermittency of some modes of renewable energy. Look out for articles about the smart grid such as this one.

Electric Vehicles
Now that the Obama administration is talking up clean energy, there’s been an explosion of interest in electric vehicles, so much so that rather than summarize articles, I’ll list pointers to them here as I encounter them:

• Willie D. Jones. New Electric Power Train Promises 160-km All-Electric Range—on a Bus! IEEE Spectrum, April 2009

Biochar
Biochar is the idea of burning carbon-containing materials in low oxygen (pyrolysis), resulting in charcoal that can be buried in the ground, improving the soil while sequestering carbon and reducing nitrous oxide (potent greenhouse gas) emissions from the soil. Biochar can also be used to produce biofuels as a byproduct. Here’s a nice YouTube summary of Australian work on biochar:

“Clean” coal
Various projects claim to be cleaning up coal. Carbon sequestration is one of the buzz words. The theory is that you can bury the CO₂ deep underground. In practice, to do so on a significant scale would be very hard. The perceived need for carbon sequestration arises from the incorrect perception that a coal producing country like Australia cannot survive a transition away from coal, a claim that is hotly contested even by former coal supporters. Here are some contrary views:

• Quarry vision: why clean coal isn’t the answer, ABC Radio National, 25 March 2009
• Quarry vision: why coal is no longer important, ABC Radio National, 25 March 2009

• Mining stalwart sees no future in carbon plan, Sydney Morning Herald, 25 April 2009

Some obstacles: worldwide emissions would amount to around 30km³ per year even compressed down to a liquid. One power station would be a lot less but still a vast volume of toxic gas to handle. Pumping it out at high temperature through a high smoke stack dissipates it into the air, and turbulence mixes it into the atmosphere quickly. A cold leak at ground level on the other hand will not dissipate fast, and can kill people in large numbers, as occasionally happens as a result of volcanic processes. Here is a detailed critique I wrote of a “clean coal” proposal for Felton in Queensland. And here is a Coen brothers ad featuring their take on clean coal:

Forest management and climate change
The forestry lobby is big on the benefits of harvesting timber. Cutting down trees, they claim, is somehow good because new growth will sequester even more carbon. The reality is a lot more complex than that; logging old growth is almost always a net loss, and managing plantations for the best overall return on carbon emissions takes careful management. This Forest, Carbon, Climate Myths slide show covers most of the major issues.

Regenerating lost forests
Watch biologist Willie Smits explain how he re-grew clearcut rainforest in Borneo, saving local orangutans – and at the same time creating work for the locals. Ignore the car ads.

Read the rest of this entry »

When Kevin Rudd announced a 5% target for emissions reductions for 2020, you could almost hear John Howard laughing from the political grave. It’s small comfort to me that in discussing climate matters since then, a Labor supporter called Rudd “Howard” by mistake. Freudian?

The science the government has in front of it says you have to reduce emissions by 25% by 2020 to save the Great Barrier Reef. Of course Australia cannot achieve this on its own because it accounts for a relatively small fraction of worldwide emissions – even if you account for its role as the world’s biggest exporter of coal (about a third of worldwide exports).

Another thing not widely talked about is that carbon emissions accumulate. Around half are absorbed by the environment; the rest dissipates very slowly over centuries. That means that if we have not achieved a target by 2020 that stops CO₂ accumulating to 550 parts per million or more, we can’t just turn off the tap and expect the atmospheric CO₂ level to drop.

How soon will the rest of the world regard carbon emissions as a serious, urgent problem? That Europe has committed to a 20% cut by 2020 is some indication.

Why should Europe care more? Partially, it’s because Europe has a stronger tradition than English-speaking countries of taking science seriously. But another factor is Europe’s proximity to the Arctic. A growing number of scientists is predicting an ice-free Arctic summer by 2015. It was a big enough shock when it was reported in 2007 that the Arctic could be ice-free in summer by 2030.

So in a sense the self-styled sceptics are right. The science has enough uncertainties that we have to be cautious about accepting predictions without a wide allowance for error. The problem is, the majority of cases that are breaking out of the modelled predictions are on the worse rather than the better side. How is this possible? With the vast bulk of “sceptics” accusing scientists who predict anything remotely bad of being “alarmist”, the natural tendency of scientists to avoid alarming claims without overwhelming evidence is accentuated. So work predicting rapid ice cap loss for example is not getting the attention it should. Another example: concerns about the possibility of the urban heat island effect (UHI) skewing the temperature trend has resulted in NASA compensating for this effect. While it is true that a temperature sensor put next to an isolated hot spot would be bad for once-off measurement, if that hot spot is not constantly being hotter, it would not add a trend to the stats.

NASA eliminates local anomalies by a process called homogenizing, where temperatures of each station are in effect corrected for excessive variation beyond others in similar terrain.

Let’s look at how over-estimating the effect of UHI could have on the temperature trend. If NASA weights down temperatures from urban area, they could be underestimating the general increase in temperatures, because some of these areas could really be heating faster than their surroundings – not just because the weather station is near an artificial source of heat.

The UHI effect is but one example of how natural caution by scientists could be underestimating the effects of climate change. There are others, which I am happy to discuss, but this example illustrates the point.

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