Category Archives: Life

Climate clippings 83

Climate clippings_175These posts are intended to share information and ideas about climate change and hence act as an open thread. Again I do not want to spend time in comments rehashing whether human activity causes climate change.

This edition contains items, exclusively, I think, in climate science and impacts. The thread is meant to function also as a roundtable to share information and ideas.

1. Climate change picked the crops we eat today

The New Scientist carries a story about how some cereals we know today were changed by the climate as we came out of the last ice age. Researchers at the University of Sheffield, UK took seeds of precursors of modern wheat and barley found with human remains in a 23,000-year-old archaeological site in Israel. They grew these together with four wild grass species that aren’t eaten today, but were also known to grow in the region at that time, and grew them under conditions replicating levels of CO2 then and also the higher levels when farming first arose 10,000 years ago.

All the plants grew larger under the higher levels of CO2, but the relatives of wheat and barley grew twice as large and produced double the seeds. This suggests the species are especially sensitive to high levels of CO2, making them the best choice for cultivation after the last ice age.

The team plan to look at whether other food staples around the world are similarly affected by elevated CO2 levels, for example millet grown in Asia and maize in North America. They also plan to compare the effects of CO2 on legumes such as peas. Continue reading Climate clippings 83

Climate clippings 71b

This post was written in October 2012 trialling the site. I’ve decided to leave it in time sequence and fiddle the numbering.

1. Did climate change shape human evolution?

There’s no evidence yet that it did according to Richard Leakey.

I’m not sure about his four key questions, though. Yes, bipedalism seems to be important as does using tools to make tools. But I can’t see the importance of migration out of Africa as important to our evolution. Apart from picking up some Neanderthal genes presumably in a palm grove somewhere in the Middle East, which did boost our immune system, those of us who left Africa are much the same genetically as those who stayed behind.

I’d say the development of language was important. If you want a fourth I’d suggest our patterns of social organisation – how we interact and how we co-operate within groups. But I don’t know how much of that is in our genes.

2. Aid for climate refugees

Speaking of climate and migration, displacement by extreme weather events does not qualify you as a refugee under present UN arrangements. The International Organisation of Migration (IOM) hopes this will change at the annual United Nations climate change summit to be held in Qatar later this year, gaining access to the Green Climate Fund (GCF) and other sources. It seems that 42 million people were displaced by storms, floods and droughts in Asia and the Pacific during 2010 and 2011.

3. Ocean heat content update

Skeptical Science recently posted on an update by Levitus et al on ocean heat content, which increases apace. Around 93% of additional warming goes into the ocean which is truly vast with, for example, an average depth of around 3,790 metres. This graph indicates the changing heat content within bands of the upper 2000m:

4. Southern Ocean research shows decrease in dense Antarctic bottom water

Antarctic Bottom Water is a massive current of super dense salty water which used to be which used to occupy the bottom mile of the Great Southern Ocean. Used to. Researchers are now able to report that the current is diminished by 60% compared to what it was in 1970.

Antarctic Bottom Water is colder than the normal freezing point and is a vast store of CO2. Understanding changes in this deep ocean current are crucial to understanding the likely future of global climate patterns as the planet warms. The researchers have not only been able to make direct observations, they have distributed buoys which should be able to provide data at times of the year when field work is impossible.

5. Plants flower faster than climate change models predict

For years scientists have been doing experiments to find out how much earlier plants will flower and leaf with global warming. A new study using field observations has found that plants are responding much faster than they had thought. Their research suggests that that spring flowering and leafing will continue to advance at the rate of 5 to 6 days per year for every degree celsius of warming.

What surprises me is that they thought they could model natural conditions in the lab.

It seems they will have to rethink the impacts of global warming on ecosystems and food production.

See also Science Daily.

6. Climate change experimentation goes bush

Another approach is to manipulate the environment on a large scale and monitor what happens. Researchers are using to control the amount of CO2 available to plants.

The idea is explore the role of “Australia’s large tracts of undeveloped land, known as bush” in storing carbon. They will be able to add carbon or take it away.

I’m not sure it doesn’t suffer from the same problems as experiments with plants, where only one variable was controlled, neglecting changes in precipitation patterns and cloudiness, for example.

7. Wind farms do not cause global warming

There has been a raft of articles in the MSM suggesting that wind farms cause global warming, mainly in the headlines, it seems.

In fact a study of some large wind farms in remote areas of Texas found local warming. The authors don’t know what’s going on but the suggestion is that thermal energy is being redistributed, perhaps by pulling down warmer air from higher altitudes during the nights.

For the spinning blades of wind turbines to increase the overall temperature of the planet some basic laws of physics would need to be rewritten.

Climate clippings 50

This is serious!

First we were told that rising temperatures would make it difficult to grow tea in
Uganda and in Kenya, then it was going to become too hot for chocolate. Now Starbucks is warning that climate change will threaten the world supply of coffee.

This story has gone viral, but I liked this neat post. Obama should indeed do something. What Al Gore said. Continue reading Climate clippings 50

Open thread on floods

We now have a number of specific threads running on aspects of the Queensland floods. This thread is for comments that don’t fit the specific threads or if you want to comment on other current floods lacking a thread, such as those in Victoria, Brazil or Sri Lanka .

These are the previous threads I can identify:

Brian on Queensland floods

Robert on Queensland floods get worse

Mark on Brisbane flood maps and up to date flood information

Brian on Toowoomba flood pics

Brian on Brisbane floods in retreat

Kim on Political cheap shots and the Brisbane floods

Kim on Quick link: Quiggin on water policy after the Queensland floods

Kim on Quicklink: Interactive map of Brisbane flood damage

Kim on Germaine Greer wrong on Brisbane floods

Mark on Social capital, social networking and the Brisbane floods

Hope I haven’t missed any.

Climate kills

According to Oxfam 21,000 people died due to weather-related disasters in the first nine months of 2010 – more than twice the number (10,000) for the whole of 2009. Their information comes from reinsurance company Munich Re.

The number of extreme weather events was 725 to September, as against 850 for 2009. The number of extreme events is likely to exceed the ten-year average of 770, but not by a large margin. This year included some particularly serious ones, such as the floods in Pakistan and the heatwave in Russia.

The Pakistan floods affected more than 20 million people, submerging about a fifth of the country, claiming 2,000 lives and causing $9.7 billion in damage. Summer temperatures in Russia exceeded the long-term average by 7.8°C, doubling the daily death rate in Moscow to 700 and causing fires that destroyed 26 per cent of the country’s wheat crop. Russia banned grain exports as a result and soon after world grain prices increased, affecting poor people particularly.

Statistics relating to extreme weather events are tricky. The number of deaths obviously relates to the severity of the individual events and how many people were living in areas where the events occurred and hence vulnerable. Continue reading Climate kills