Archive for the ‘Environment’ Category

Is the IPCC report ‘News’?

September 27, 2013
For a couple of hours this was the headline at the BBC News Web Site. By the evening it was the fourth story after a 'Tax Break for Married Couples'.

For a couple of hours this was the headline at the BBC News Web Site. By the evening it was the fourth story after a ‘Tax Break for Married Couples’.

Why do I find myself unmoved by the release of the fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC)? Because despite the epic scale of the report, on my quick perusal of the summary, I see nothing ‘new’.

And the BBC seems to concur. Although it made the lead story on the BBC web site for a couple of hours, it was down to fourth position by the evening and made only the third story on the television news. At least it was ahead of the inane story about why ballet dancers don’t get dizzy. [Aside: since when was that considered ‘News’?].

One aspect of the news did make me smile. Because of the ‘pause’ in rise of the average air temperature above the land surfaces of the Earth, sceptics are now saying that our understanding of climate change must be fundamentally flawed. This made me smile because while the ‘temperature curve’ was rising the sceptics were arguing that the data could not be relied upon. Now that it has slowed down, the data is all of a sudden more trustworthy!

But levity aside  the report is grim. It reads like a list of battle casualties where new intelligence reveals that those previously listed as ‘missing in action’ are now confirmed as ‘fatalities’ or ‘injured’. The report list each casualty detailing our state of knowledge of the extent of their injury. I have included a couple of snippets below.

So the report is as clear as it can be, but it leaves one basic question unasked, and of course unanswered:

What are we going to do about all this?

Snippets

  • The atmospheric concentrations of carbon dioxide (CO2), methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years.

  • CO2 concentrations have increased by 40% since pre-industrial times, primarily from fossil fuel emissions and secondarily from net land use change emissions.

  • The ocean has absorbed about 30% of the emitted anthropogenic carbon dioxide, causing ocean acidification

  • Over the last two decades, the Greenland and Antarctic ice sheets have been losing mass, glaciers have continued to shrink almost worldwide, and Arctic sea ice and Northern Hemisphere spring snow cover have continued to decrease in extent (high confidence)

  • Ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90% of the energy accumulated between 1971 and 2010 (high confidence). It is virtually certain that the upper ocean (0−700 m) warmed from 1971 to 2010, and it likely warmed between the 1870s and 1971.

  • Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. In the Northern Hemisphere, 1983–2012 was likely the warmest 30-year period of the last 1400 years (medium confidence). 

  • The rate of sea level rise since the mid-19th century has been larger than the mean rate during the previous two millennia (high confidence). Over the period 1901–2010, global mean sea level rose by 0.19 [0.17 to 0.21] m

Why Measuring Stuff Matters

April 12, 2013
We live in a world in full of vast structures which change imperceptibly slowly, and tiny structures which change imperceptibly quickly. Measurement extends our senses into these realms.

We live in a world in full of vast structures which change imperceptibly slowly, and tiny structures which change imperceptibly quickly. Measurement extends our senses into these realms.

One of the wonders of human psychology is how we deceive ourselves about the true nature of the world.

One of the triumphs of the human psyche is that – even while trapped within our own deception – we can break through and discover uncomfortable facts about the world. Facts that allow us to understand our limitations and learn how to overcome them. Experiments which allow us to experience our own blind spots are a classic example, but in fact we go much further than that.

We trust our measurements more than we trust ourselves. From basic measurements of length and time and mass, we have developed an infrastructure that allows us to make measurements – often simple in themselves – through which the nature of the Universe is revealed to us – despite our very human biases and blind spots. Sorry that sounds so pompous – but that’s how it is!

We make measurements and then we trust them more than our own eyes. If sensors tell us a light is flickering 100 times a second – we believe it – even though our eyes see nothing. If measurements indicate that continents are moving apart at 2 centimetres per year – we believe them – even though we experience nothing.

We have developed techniques of measurement that allow us to see ourselves and our world in richer detail than at any time in human history. Looking just through the open tabs on my browser I see have measurement ‘stories’ on all these themes:

In each case above, measuring things and comparing them with our expectations doesn’t simply provide a number – it allows us to view the world in new ways. And it allows us to extend our vision into the realms of the otherwise imperceptible, or the overwhelmingly vast. And that is why measurement matters!

Solar power gets real

April 7, 2013
Some of the long parabolic reflectors in the Shams 1 electric power plant in Abu Dhabi.

Some of the long parabolic reflectors in the Shams 1 electric power plant in Abu Dhabi.I love to see this kind of machinery made real. Image from the Shams Image Gallery

I love seeing pictures of real solar electricity generating plant. In a sunny country where peak sun coincides with peak electricity demand – for air conditioning – this makes complete sense. I can’t speak for the finances, but in terms of EROEI, this looks a sensible energy investment.

The BBC recently showed footage of the SHAMS 1 plant in Abu Dhabi. The enterprise also has a web page and wikipedia entry.

There are loads of ways to generate electricity with solar energy. I don’t know that one technology can yet be said to make better sense than any other – but this plant looks relatively low tech and relatively expandable. This must be like in the early days of steam engines or powered flight where people struggled to find optimal engineering solutions.

This plant in fact appears to be a solar-assisted gas-fired steam turbine, where the solar heating is used to reduce the gas consumption, but where gas can be burned as back-up at night or on cloudy days.

There was a mention of the ability to store the solar heat for short periods and so spread the generating time, but it didn’t sound as though this had been implemented.

Why am I mentioning this? Because lots of places in the world are sunny – and many of these places have lots of space. This is unlikely to be a good technology for use in the UK, but for countries near the Equator such a plant must look attractive – exploiting a natural and inexhaustible resource and delivering valuable electricity.

It looks to me like a glimpse into the future. A sustainable future.

What should we do after we stop Global Warming?

April 5, 2013
The Keeling Curve using data up to 2150. Back in 2013 no one would have imagined that we could make it peak at only 512 ppm.

The Keeling Curve using data up to 2150. Back in 2013 no one would have imagined that we could make it peak at only 512 ppm. I think this is one of humanity’s greatest collective achievements. Which problem should we tackle next?

Sometimes I like to imagine having different problems to solve. Somehow problems we face right now seem very hard, whereas non-urgent problems, or other people’s problems  seem to have obvious solutions.

While musing on this I considered the possibility that we had collectively solved the problem of Global Warming and Climate Change. Even just imagining this lifted my spirits. And so I was able to wonder: what problem should be next? If we can solve that one, surely there is nothing we can’t do?

“Hang on!” I hear you say, “Before you go solving humanity’s next eco-problem, could you just explain how we solved the Global Warming ‘thing’?”. Sure.

Well it took a few years of the usual equivocation. But then in 2019 several events conspired to focus the minds of governments. Firstly there was the 40% reduction in the US grain crop and a similarly bad year in Russia. This was the first summer in which the North Pole was ice-free for months – and this somehow shocked people and changed popular sentiment – even amongst ‘right-wing’ media.

The previous bitter winter in Northern Europe had been followed by a summer heat-wave with temperatures of 45 degrees in Scotland. These twin seasonal extremes had killed thousands of people and left crops and livestock devastated. So when governments met in the blistering heat of the 2020 International Brighton Conference – some how everything came together. Governments competed with each other to show how radical they could be.

Things moved quickly. During the following summer a vast international flotilla created millions of square kilometres of fog-mist in the Arctic Ocean, reflecting the summer heat and tying the circumpolar winds as far north as possible. After two years, the arctic sea ice began to thicken and its summer extent began to grow back. Even the permafrost began to cool again as a the snow-line moved south.

In the developed nations, radical measures were finally accepted. Enforced car-sharing, compulsory insulation of houses, night time switch-offs and widespread tele-working reduced  carbon emissions by 30% in just three years. The results could be seen on the Keeling curve. Then the 2043 eruption of Mount Biggo-Wunno dramatically affected global temperatures for the next decade, and despite the devastation, helped moderate the warming in both hemispheres.

Of course this just slowed the rate of increase – it took the rest of the century to turn around the rising CO2 levels, see them stabilise at the previously unthinkably low 512 ppm, and finally fall for the first time in 2092. There were plenty of problems along the way – and plenty of consequences of climate change to cope with.

During the first decades of the century, our understanding of climate, weather and computing all evolved exponentially. Our ability to make informed decisions was transformed with the 2029 implementation of the devolved computing paradigm (DCP). Immediately meteorologists were able to run realistic models that could predict real weather 3 weeks in advance. And climate modellers found that they could finally predict the effects of specific policy actions in way that convinced politicians.

But the modelling revealed what we had already known one hundred years previously. Without anthropogenic interference, the Earth would have been drifting towards a new ice age. Now, having changed our lifestyles and geo-engineered specific solutions, could we really let that happen just because it was a ‘natural’ trend?

Lessons from a cold spring

April 2, 2013
A helicopter delivering emergency supplies to farmers in Northern Ireland. Picture Credit Paul Faith/BBC

A helicopter delivering emergency supplies to farmers in Northern Ireland. Picture Credit Paul Faith/BBC

It’s been cold in the UK this spring 2013. Much colder than usual and even now at the start of April, the average temperature in London is only around 4 degrees Celsius.

In the North there is still snow on the ground, electricity supplies have been disrupted and livestock killed. The Daily Mail is shocked. The Guardian is concerned. And some even suggest this is a harbinger of changing climate resulting from last summer’s exceptional loss of Arctic Sea Ice.

Personally I don’t know if this weather does or does not result from the shocking Arctic Sea Ice decline. But I think there is one very important lesson we can learn.

This spring is only fractionally colder than most UK springs. And already we are losing livestock, crops yields are affected (so raising prices), heating bills are higher than expected, and it will cause significant road damage.

Now imagine if this happened every year. Or imagine if it happened for twice as long. Or for twice as long every year. In terms of climate change this would be the smallest of shifts. A small change in the position of atmospheric circulatory patterns. But life in the UK would be more unpleasant and more expensive.

At Protons for Breakfast people often askIs Climate Change a bad thing? Could there be a good sides to it? And of course Climate Change is not of itself good or bad. And there can be positive aspects to it.

What this spring brings home to me is how much our way of life is adapted to this particular climate, and how much even tiny changes leave us flumoxed. And that while we can adapt to changes – adaptation will cost money.

When climates have changed in pre-history populations have moved or adapted. But at no time in pre-history has the Earth supported 7 billion human beings. We now live highly optimised lives: crop yields that would have been an achievement 30 years ago would now be considered a disaster.

So even though climate change of itself is neither good nor bad. In almost every human situation, even a small amount of change – colder or warmer, wetter or drier – brings trouble, and extra costs.

World Population estimates from 1000 AD to 2011. Data fromWikipedia

World Population estimates from 1000 AD to 2011. Data fromWikipedia

Ahhh EROEI

March 30, 2013
The Ratio of the Energy Returned divided by the Energy Invested in producing electricity. The Green bars are global estimates and the purple bars apply to the US. There is considerable uncertainty in the numbers

The Ratio of the Energy Returned divided by the Energy Invested in producing electricity. The Green bars are global estimates and the purple bars apply to the US. There is considerable uncertainty in all the numbers.

How should we decide on the mix of technologies to use to generate electricity? There are pros and cons for all the choices.

  • Coal is cheap but emits carbon dioxide.
  • Gas is a bit more expensive but emits 50%  less carbon dioxide.
  • Nuclear requires eye-watering up-front investment but is low carbon.
  • Wind energy is intermittent but sustainable

So it is interesting to make quantitative comparisons between the differing technologies. We have many choices in comparing parameters. Initial costs; running costs;  immunity to world fuel prices; sustainability – the list goes on.

One interesting choice is EROEI: the Energy Return on Energy Invested. It is the answer to the sum:

EROEI = Useful energy produced ÷ Energy invested

So for example, if I use one unit of energy to dig coal from the ground, ship it around the world,  and then burn it to power a steam turbine and make electricity, how many units of electrical energy do I generate?

This is a simple question to ask, but a difficult one to answer. For example, one would obviously consider the energy used in shipping the coal. But what about the energy used in building the ship? Or some fraction of it? Using standardised rules one can produce estimates of EROEI and the results – in a chart at the top of the article are interesting.

Several things struck me about this chart

  • First there is massive discrepancy between world-wide coal (18) and US coal (80). This is presumably because of the ease of extraction of US coal, and the short distance from mines to coal-powered  electricity-generating plant. The large numbers in each case help explain the popularity of coal in generating electricity both world-wide and in the US. The energy return of course takes no account for energy which might be needed to cope with the consequences of the massive carbon dioxide emissions, or the appalling environmental legacy of coal mines.
  • Second is the number for wind (20 or 18) – which is more-or less the same as coal. At Protons for Breakfast many people ask whether in energy terms wind power is ‘worth it’. The answer from these studies is a definite ‘Yes’. However I suspect that the time to reap this return on investment may be longer which affects the financial return on investment.
  • On reflection I was not surprised that hydroelectricity represents the best EROEI, but of course this does not cover the environmental costs of such schemes.
  • The low value for gas (7 or 10) surprised me. I suppose this reflects the costs of discovery, transport, storage and delivery.
  • And finally the numbers for solar energy more or less match the numbers for nuclear energy. These are not specific to the UK and so the same numbers are unlikely to hold here. However I was surprised at the low number for nuclear power and the relatively high value of Solar Photovoltaic generation.

EROEI is not a magic number – but it is a fundamental number. If this number is below unity, then in energy terms the activity makes no sense. And if the number is close to unity, then the activity is barely worthwhile unless there is some other benefit. Scientific American suggest that activities where the EROEI is below 5 represent a borderline below which electricity -generating technologies are no longer worthwhile. It is interesting that several current technologies – including nuclear power –  come close to that suggested border.

References

Mason Inman: Scientific American 2013: This contains lots of links to his sources – but many of these are behind pay walls 😦

Wikipedia EROEI  This contains lots of links to sources – but many of these are behind pay walls as well 😦

Which kettle to choose: Gas or Electric?

December 16, 2012
Which kettle is more energy efficient?

Which kettle is more energy efficient?

Boiling water is an essential pre-requisite for the preparation of tea – and as such it is an activity central to the cultural life in England. For example, six cups of tea were drunk while preparing this article. Boiling water is also an energy intensive activity and so for all the usual reasons, it’s a good idea to boil water in an efficient manner. But should one use an electric kettle or a gas kettle? This was the subject of my first ever blog posting back on 1st January 2008 – and because that blog is no longer available, I thought it worthwhile to re-post and re-visit the problem now.

Initially, I was confident that using a gas kettle would save energy compared with an electric kettle. This is because electricity is generated at power stations which have an overall efficiency which is often less than 40%. That’s a guideline figure for any thermally-generated electricity (coal, gas or nuclear). It means that roughly 60% of the energy content of the fuel is lost before the electricity leaves the power station. Some gas generation using CCGT technology is more efficient: up to 60% in the best cases but relatively little electricity is generated this way. Additionally, typically 10% of the energy which leaves the power station is lost in transmission to my home. So only perhaps 36% of the original energy content of the fuel is fed into my kettle element.

Since raw methane is distributed directly to my kitchen, all a gas kettle has to do is capture a bit more than one third of the chemical energy and I would be better off than using electricity. So I was confident that by using a gas kettle I would be making an environmentally friendly decision.

Was I right? I compared the time boil 1 litre of water with the time expected if the device used the energy supplied to it in the kitchen with 100% efficiency. I then applied a ‘Network Efficiency’ factor.

The Electric Kettle (2 kW) took 210 seconds to boil 1 litre compared with an expected time of 188 seconds, so the ‘in-kitchen’ efficiency was 90%.

The Gas kettle had three burners:

  • The 1 kW Burner took 680 seconds to boil 1 litre compared with an expected time of 380 seconds, so the ‘in-kitchen’ efficiency was 56%.
  • The 1.75 kW Burner took 450 seconds to boil 1 litre compared with an expected time of 210 seconds, so the ‘in-kitchen’ efficiency was 48%.
  • The 3 kW Burner took 380 seconds to boil 1 litre compared with an expected time of 127 seconds, so the ‘in-kitchen’ efficiency was 33%.

The Microwave Oven (800 W) took 720 seconds to boil 1 litre compared with an expected time of 300 seconds, so the ‘in-kitchen’ efficiency was 66%.

And the results? 

Result #1 Heating water using a gas kettle is a more efficient use of fuel, but only at low gas settings. And even at low settings, a gas kettle wastes 50% of the energy supplied to it. Using higher gas settings wastes an even larger fraction, up to 67%!

Result #2 Heating water using an electric kettle is the fastest way to heat water, being roughly twice as fast as the high-power gas burner – and with very similar efficiency.

Result #3 Using a microwave to heat water was definitely the least efficient of any of the methods – but this result may change when heating small quantities of water.

Overall the data indicate that gas kettles are amazingly wasteful. In subsequent articles I will be looking to see if they really are as bad as they seem.

The efficiency of different ways of heating water. The blue dots show the efficiency with which fuel supplied to the kitchen is converted to heat energy in the water. The red dots show the efficiency when taking account of the conversion of chemical energy from the primary fuels. Teh shocking news is that even when boiling water slowly with gas, around half of teh energy is wasted! If one is boiling the water quickly then there is no difference in overall efficiency. The efficiency of different ways of heating water. The blue dots show the efficiency with which fuel supplied to the kitchen is converted to heat energy in the water. The red dots show the efficiency when taking account of the conversion of chemical energy from the primary fuels. Teh shocking news is that even when boiling water slowly with gas, around half of teh energy is wasted! If one is boiling the water quickly then there is no difference in overall efficiency. The efficiency of different ways of heating water. The blue dots show the efficiency with which fuel supplied to the kitchen is converted to heat energy in the water. The red dots show the efficiency when taking account of the conversion of chemical energy from the primary fuels. Teh shocking news is that even when boiling water slowly with gas, around half of teh energy is wasted! If one is boiling the water quickly then there is no difference in overall efficiency.

The efficiency of different ways of heating water. The blue dots show the efficiency with which fuel supplied to the kitchen is converted to heat energy in the water. The red dots show the efficiency when taking account of the conversion of chemical energy from the primary fuels. The shocking news is that even when boiling water slowly with gas, around half of the energy is wasted! If one is boiling the water quickly then there is no difference in overall efficiency between using gas or electricity – they both waste two thirds of the energy!

Experimental Details

  • I began by measuring the initial temperature of water from the tap which turned out to be close to 10 Celsius.
  • I then weighed the vessel (electric kettle, gas kettle or glass jug ) before and after filling with water.
  • I estimated the energy required to raise water from 10 °C to 100 °C using the measured water mass and the heat capacity of water (roughly 4200 J per °C per kg and rather constant in this temperature range).
  • For the electric kettle I used its power rating of 2000 W (which I had previously measured and found to be a good estimate.)
  • For the gas I used data for the gas burners which indicated they had a rated power of 1 kW, 1.75 kW and 3 kW.
  • For the microwave (rated power 800 W) I used a power meter to record the actual consumed power (1240 W)
  • I then recorded the time taken for the water to reach 100 °C and compared with the expected time if the device were 100% efficient.

I then factored in the efficiency of the network, assuming that

  • For electrical heating: 36% or the original calorific energy of the fuel was delivered to the house.
  • For gas: 90% of the original calorific energy of the fuel was delivered to the house, with the remainder being used to power the pumps on the gas pipeline.

Finally on rewriting this in December 2012 I decided to re-check my numbers. I boiled the same kettle on the 1.75 kW burner and got an ‘in-kitchen’ efficiency of 41% compared with 43% that I estimated previously. So I estimate that these numbers have an uncertainty of around 1% or so.

Energy Prices: Reality Bites

October 28, 2012
Dilbert Confusopoly

Dilbert explains how a confusopoly works.

Worldwide, governments are ‘in denial’ about the inevitability of higher energy prices. At least in public. Somehow – despite some intelligent policies – it has become impossible for politicians to speak honestly and with a longer term perspective.

  • The supply of energy is critical to a nation’s security and this is a responsibility which governments cannot abdicate.
  • But neither can governments wave a wand and make market forces disappear.
  • Climate change is a reality and – eventually – governments will have to respond no matter how unpopular this is.

In the UK David Cameron promised to insist that companies sell energy at the cheapest price to their customers. It seems like a simple enough promise, but I have great faith the confusopoly will survive. Why?

Well firstly, neither governments nor customers are in any position to argue. The government sold national energy assets decades ago and cannot afford to buy them back. And the UK does not possess a great excess of energy supply capacity over energy demand. So one way or another, the customers will have to pay. We are in a tight corner.

Secondly, the UK government committed itself reducing carbon emissions to 20% of its previous level by 2050. To achieve this it offers subsidies to producers of renewable electricity and to homeowners who insulate their homes. These subsidies are paid for by increasing the price of electricity. I think this is intelligent, but many do not.

In the USA I was astonished to see presidential candidates trading statistics about which of them would increase coal mining and gas extraction faster and so lower prices. The US elections are essentially a popularity contest and so it is not really surprising to see such exchanges. But in reality electricity generation from coal is an environmentally disastrous technology and – in part driven by rulings from the Environmental Protection Legislation – it is already being replaced in the US by gas – which in the US is probably (borderline) a good thing.

In France – Mr Hollande is introducing a system in which he seeks to hold back market forces and to make the price of electricity depend upon who you are and where you live. This is an extension of the US system I described a few months ago in which electricity becomes more expensive the more you use – a market-based system which discourages excess use. The problem with the French system is that – like the common agricultural policy – it is massively bureaucratic and encourages people to extract the maximum subsidy rather than to reduce use.

In my opinion – and this is why I have never been a popular person – we should welcome increased energy prices relative to  other costs. It means that renewable energy become more affordable. It means we will conserve energy more (while complaining I admit) and emit less carbon dioxide.

And if we want to spend money helping disadvantaged people – and I think we should – we should spend it to help them use less energy rather subsidising their use of more energy.

===============

Confusopoly‘: a small number of firms make the price of their  offering so confusing that no one can work out which company offers the best deal. Mobile phone operators and Insurance Companies are the masters of this art, but Energy Companies give them a good run for their money.

I told you so

October 20, 2012
In 1981 Hansen et al made predictions for the change in global mean temperature expected over the course of the coming century. The figure shows their predictions along side 4 independent estimates of what has actually happened.

In 1981 Hansen et al made predictions for the change in global mean temperature expected over the course of the coming century. The figure shows their predictions along side four independent estimates of what has actually happened.

According to Gore Vidal, the four most beautiful words in the English language are “I told you so”. My hero James Hansen can justifiably speak those words, but I am sure they don’t feel beautiful to him.

In 1981, together with six NASA colleagues, he published a paper in Science magazine entitled ‘Climatic Impact of Increasing Atmospheric Carbon dioxide‘. Science magazine won’t let you read it but it is available online here. The paper is not that difficult to understand and if you are curious about these things, it’s a good read. I particularly liked the inclusion of a simple analogy:

“The surface temperature resulting from the greenhouse effect is analogous to the depth of water in a leaky bucket with constant inflow rate. If the holes in the bucket are reduced slightly in size the water depth and water pressure will increase until the flow rate out of the holes once again equals the inflow rate. Analogously, if the atmospheric infrared opacity  increases, the temperature of the surface and the atmosphere will increase until the emission of radiation from the planet again equals the absorbed solar energy.”

The figure at the top of the page shows Figure 6 from their paper on which I have overlaid four independent estimates of what has actually happened since then. At the time the paper was published,  global mean temperature was declining and the predictions were thus extremely bold. However, looking back the authors predictions now seem conservative. And indeed the authors were careful and conservative, though clear about specific predictions.

In the summary they state

“Potential effects on the climate in the 21st Century include the creation of drought-prone regions in North America and central Asia … erosion of the West Antarctic Ice Sheet … and an opening of the fabled NorthWest passage”

Well, North America has been prone to drought, and the North West passage now regularly opens in summer. Thankfully the West Antarctic Ice Sheet seems relatively stable.

All through the paper the authors consider the uncertainties arising from the simplicity of their model and the many poorly-understood effects – such as cloud cover and solar variability – which affect climate. However, they test their predictions against plausible variations in these factors and find that the predictions of warming are robust against a wide range of plausible feedback effects. They conclude with a wider non-scientific perspective

Political and economic forces affecting energy use and fuel choice make it unlikely that the CO2 issue will have a major impact on energy policies until convincing observations of global warming at in hand. In light of historical evidence that it takes several decades to complete a major change in fuel use this makes large climate change almost inevitable.

However the degree of warming will depend strongly on the energy growth rate and the choice of fuels for the next century. Thus CO2 effects on climate may make full exploitation of coal resources undesirable. An appropriate strategy may be to encourage energy conservation and develop alternative energy sources while using fossil fuels as necessary during the next few decades.

The Climate change induced by anthropogenic release of CO2 is likely to be the most fascinating global geophysical experiment that man will ever conduct. The scientific task is to help determine the nature of future climatic effects as early as possible. The required efforts in global observations and climate analyses are challenging, but the benefits from improved understanding of climate will surely warrant the work involved.

To me these views seem modest, realistic and optimistic. But I bet that although James Hansen and his colleagues predicted the climate 30 years ahead, they never guessed that in the 21st Century the US would have senators such as Paul Brown.

To understand such ignorance we have to turn again to Gore Vidal:

The United States was founded by the brightest people in the country – and we haven’t seen them since.

Acknowledgement: This article is based on a blog story at Real Climate:

Arctic Sea Ice 2012

September 10, 2012
Sea Ice Summer 2012

Daily satellite records of the extent of Arctic Sea Ice since 1980. The regular pattern of of melting and re-freezing appears to have been significantly disturbed in recent years. Click for a larger version. Data from NSIDC – see text for links.

I have returned from my holidays and the children are back at school. So I guess summer is over and it’s time for my annual check on how the Arctic sea ice is doing. … What?

The summer minimum of Arctic sea-ice extent will probably be reached in the next couple of weeks but already the previous minimum sea-ice extent has been undercut by more than a half-a-million square kilometres. Currently there are only around 3.5 million square kilometres of sea ice. The previous minimum value in 2007 was 4.2 million square kilometres. In the 1980’s – when I was twenty-something and unconcerned about Climate Change – a more typical figure would have been 7 million square kilometres of sea ice.

The graph at the head of the page shows the data which is collated from spreadsheets available here, here (old data) and here (new data). A multitude of graphics are available at the US Snow and Ice Data Center.

The BBC has reported this story pretty thoroughly and even The Register is shocked! But I am almost lost for words.

  • First we need to remind ourselves that nobody – and I mean nobody – knows what is going to happen next. However it looks like the people modelling the volume of arctic sea ice have their models just about right. Even while the sea-ice area was relatively stable, the ice thickness was probably declining. Once a minimum thickness is reached, the coherent ice sheet is broken apart by weather. The reflectivity of the surface then changes and much more solar radiation is absorbed. It is interesting to note that in contrast with the recent changes in summer sea-ice, the sea-ice winter maximum appears be only declining rather slowly.
  • If the volumetric modelling is correct, then as I mentioned previously, over the next few years – and I mean years and  not decades – summer ice in the Arctic will reduce in extent dramatically. It is quite plausible that even by 2020 we could have a few days each year in which there is no coherent ice sheet in the Arctic.
  • Once the sea-ice melts in summer then  each year the number of days that the ice melts will increase and summer ocean surface temperatures will begin to rise above zero. It is not clear that we will ever reach a situation in which sea ice will not form in winter – but it is possible. Remember that summer in the Arctic is more intense than anywhere else on Earth. It is a shocking fact that during each day of the Arctic summer, more solar energy falls on each square metre of sea or ground in the Arctic than ever falls on a square metre of ground in the tropics or deserts.

In my opinion this data speaks more eloquently than either myself, or reams of scientific papers discussing global temperature. This data speaks eloquently and it is saying very clearly – “something dramatic is happening in the Arctic: be concerned.”


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