Monday, 19 October 2015

Climate schizophrenia

The USA is a mighty strange place. It produces some of the world's best scientists and most effective technology entrepreneurs. It also produces a political culture dominated by money and fiercely hostile to anything that challenges the power of the ruling elite.

Only in the USA do we see so many powerful politicians in simple denial of the facts that world temperatures are rising and will continue to rise unless we active decisively. It's not because the USA is magically exempt from the consequences of climate change. Quite the contrary:

Overheating:  A study by US scientists showed that US residents' exposure to temperatures over 35 degrees will increase 4 to 6 fold within 30 years. The increase is due to both climate change and population growth.

Sea-level rise:  A recent study by Princeton scientists has confirmed predictions that sea-level will rise 1 metre by 2100 and continue to rise thereafter. The land on which 30 million Americans live will ultimately be lost to the sea. Threatened cities include Boston, New York, Miami, New Orleans Long Beach and even Sacramento.

But all that's decades, even centuries, in the future. Is the problem a kind of short-sightedness?  Well not really. Here's what's under their noses.

Drought.  California is in the fourth year of a severe drought, the worst in its history. This has produced forest fires that have killed six people and destroyed 1,000 homes (New Scientist, 26/9/15, p5). The effect of climate change is easy to understand here. Apart from just drying out the vegetation it makes precipitation fall as rain, which runs off, not snow, which would replenish the underground aquifers.

Or is the USA still so obsessed with the Middle East that nothing else registers? Again no.

War.  Syria's civil war began with protests in cities like Homs and Hama in 2011. Conditions in these cities had been exacerbated by Syrians seeking refuge from the 2007-11 drought, the most severe on record. And the severity of that drought was due to - have you guessed? - climate change. Actually Syria's rainfall has been declining for about fifty years whilst its population has risen four or five fold in that same period.

Of course, it's never just climate change. Population growth, rising consumer demand, religious extremism, government policies - or the lack of them - and just bad luck are all part of the causal chain.

It's just that so many US leaders refuse to see the obvious for fear that they'd be obliged to support policies of restraint that would threaten their comfort and the profits of their corporate sponsors.

But you knew that, didn't you?

Wednesday, 26 August 2015

How Climate Change threatens the world's natural heritage

Not just Palmyra.

In July New Scientist reported that 35 World Heritage sites are threatened by climate change. That's nearly one in six of the sites listed because of their natural value. They include shrinking glaciers in Argentinia's Los Glaciares National Park and the washing away of birds nests by higher sea levels in Germany's Wadden Sea.

In  most cases climate change isn't the only factor. In Los Glaciares alien species, like cows and dogs, and increased visitor numbers create problems. In the Galapagos its much the same whilst in Mexico's Butterfly Biosphere Reserve commercial logging is a factor. Of course, these factors threaten that large majority of sites and habitats that aren't special enough to have World Heritage status but which are still important for the preservation of biodiversity and recreation.

Look behind the headlines and you see the same four causes:
  • More people - who need homes and food.
  • More prosperity - especially in China - which increases the demand for meat, minerals, travel, etc.
  • More development - both to meet local needs and to provide exports to the developed countries.
  • Unnecessary use of fossil fuels - driving climate change.
 Consumer capitalism has lifted billions out of poverty but it now threatens the natural world.

Can renewables meet the need?

A recent tweet celebrated the supposed fact that at peak, recently, Germany derived 25% of its power from solar. The source given was data published by the Fraunhofer ISE at  But is the claim true?

Actually no. The highest proportion in recent weeks was reached during August 2nd when a combination of low demand, low winds and strong sun produced about 56% of Germany's electric power from solar pv. A very good result - though obviously excluding fuels used for space heating, travel, etc.

But it's a power number - a measurement over a short time - specifically the middle of the day. There is no solar power at night and not much in the early morning and evening. A bit of rough analysis for a more representative day, 27 July in fact, shows that solar produced 22% of the power at peak but 10% of the day's energy. Extra investment in solar PV could increase the peak as much as you like - even to 100% - but that would still need over 50% of the energy to come from somewhere else (possibly wind or a storage system).

And this is mid summer.

A similar analysis for January shows a solar PV power peak of c8% but providing only c2% of the day's electricity. And the average over that week is much worse.

Is wind the answer? Sort of. Germany gets more energy from wind than from solar PV and it's available at night and in winter. But it's even less predictable than solar. At midnight on January 5th it provided just 3% of the needed electrical power.

Moreover periods of low wind can last for days - there was almost no wind for the whole seven days starting January 17th.

There are partial low-carbon solutions - nuclear, tidal, hydro, import of power from very large new solar farms in north Africa and various kinds of storage - but they all have their own problems.
Any responsible plan for our energy future must show how it would cope with periods like 17 to 14 January - and at what cost.

Sunday, 16 August 2015

Halfway to catastrophe!

Two weeks ago New Scientist reported the results of a kind of mini systematic review of global temperatures since 1850. In it Michael Le Page argues that the best baseline period - to give the temperature before global warming started - is 1850 to 1899. For convenience some temperature series use 1880-1899 as their baseline but this is misleading because temperatures in the 1880s were depressed by the eruption of Krakatoa.

When the five available temperature series are adjusted to use 1850-1899 as baseline it's clear that four of the five will show more than one degree of warming before the Paris IPCC conference this Autumn.

That's halfway to the the two degree level generally thought to imply a strong probability of catastrophic climate change.

Le Page continues with the prediction that unless we take "drastic action" the Earth will reach that two degree point by around 2050.

Friday, 24 July 2015

Natural heritage in danger

197 World Heritage Sites were selected because of their natural character. Of these 35 are threatened by climate change - the nearest being the Waddensee in north Germany.

Ironically the only natural character site to lose its world heritage status, the Arabian Oryx Sanctuary, did so because Oman decided to allow oil prospecting!

Thursday, 23 July 2015

Sea level rise - No anomaly

Climate scientists had been concerned by an apparent slowing of sea-level rise over the last decade despite the increasing volume of run-off from glaciers. A recent paper in Nature Climate Change (DOI: 10.1038/nclimate2635) resolves the anomaly.

The authors showed that the rate of sea-level rise for 1993 to 2004 had been overestimated by about 20% due to inadequate calibration of the satellite-mounted altimeters. The new value, 2.6 to 2.9 mm/year, implies an acceleration in the rate of sea-level rise since 2004.

Friday, 7 November 2014

Repeating the fate of Carthage?

Did you know that the Romans sowed the fields of Carthage with salt after defeating it in the second Punic War?

If so, you know a myth!  Apparently this was invented quite recently!

Unfortunately, our salting of fields is all too real. An international research team points out that poor irrigation practice often leads to salt deposition causing production losses. They cite research showing that in India salt-affected fields produce 40 to 60% less than those not affected.  The team estimated the annual costs due to lost crop yields and additional costs at $27 billion per year.

Salt damage can be reversed - but it's not cheap.