200 years of data shows climate changes accelerating

The Radcliffe Meteorological Station in Oxford has just celebrated 200 years of daily weather observations, possibly the longest run of daily records for any single location in the world. Now located in the garden of Green College beside the old observatory building, adjacent to the new Mathematical Institute, it has temperature and rainfall records continuous from January 1815, as well as irregular observations of rainfall, cloud and temperature from 1767 to 1814.

"Green Templeton College in Snow 2009". Note the weather station's Stevenson screen visble on the right of the photo.
Licensed under CC BY 3.0 via Wikipedia.

These records show some worrying statistics, indicating that Britain's weather is becoming more extreme as it becomes warmer (a phenomenon due to in part to warmer air being able to carry more energy and moisture). 2014 was Oxford’s warmest year since records began in 1815, and part of a very warm trend since 1990. The average annual temperature for 2014 was 11.5°C (53°F), 1.8 degrees Celsius (over 3 degrees Fahrenheit) above the 200-year average of 9.7°C (49½°F), a significant difference in weather terms. This was accompanied by extremes of wet or dryness. September 2014 was the second driest on record and yet the winter rainfall total for December 2013 to February 2014 was the wettest winter quarter again since 1815. As a single month January 2014 was the wettest of all winter months with rainfall of 146.9mm (almost 6 inches) was nearly three times the month’s long-term average in Oxford of 52.9mm.

Although these figures may sound quite unexceptional,they are a clear indication that weather is changing, and much more rapidly over the past couple of decades than for most of the previous 180 years.

Does your car achieve its official miles per gallon?

My car gets 60.47mpg¹.  How do I know?  Because I have recorded every litre of fuel put into it since I bought it three summers and four winters ago, and trust that the odometer gives me a reasonably accurate mileage driven.

So am I pleased – it does sound like a decent fuel economy, after all?  Well, not wholly, as although it is almost twice the number of miles per gallon of its predecessor, it is still a lot lower than the 85.6mpg the manufacturer's website would have you believe that I should be getting.  And if you've been sold a promise of fuel economy, to get a result that's almost 30% worse is more than a little disappointing. Of course, that also means I am pumping out 30% more CO₂, the main gas contributing to climate change, than I expected.

So does that mean I am a poor driver?  Probably not; when I shared a car with another driver I consistently got better consumption than she did, largely through more gentle acceleration.  I am always conscious of my consumption and try to avoid sharp braking, and hardly ever use the air-conditioning (which can be a huge draw on engine power, thereby reducing miles per gallon).  What it really means – and this seems to be an effect that is particularly pronounced with smaller more economical cars, that the official figures are wrong.

And how can this be?  Well, the official test figures are undertaken using something called the New European Driving Cycle (NEDC) test.  This places the test car on a rolling road, and a highly trained driver then drives as gently as he or she possibly can, to achieve the reported figures.  Moreover there are some tricks of the trade that be used to flatter the results.  Tyres may be over inflated to reduce rolling resistance; the car may be run in a higher gear than would be normal for the speed; special lubricants (and never oil that's been in the engine for a year) can be used, and weight is minimised by removing the spare wheel.  In extremis, the alternator may even be disconnected, the radio aerial removed or door handles and other protrusions taped over to reduce resistance.  All are apparently permitted – and of course there are no traffic lights, roundabouts, head winds or traffic jams to reflect reality.

A report from the International Council on Clean Transportation confirms this.  According to their website:

Comparison of official and "real-world" fuel consumption and CO₂ emission values for passenger cars in Europe and the United States, shows that the average discrepancy between them rose from less than 10% in 2001 to 25% in 2011.

The EU has got wise to this.  They realise that the tests, which are fundamentally unchanged since first introduced in 1970 no longer reflect reality and are too easily "gamed".  Instead they would like to introduce a new World Light Vehicle Test Procedure (WLTP).  However most manufacturers are opposing this, as they fear that they will be unable to meet EU-mandated fuel economy standards for new vehicles and incur huge fines.

I have some sympathy for the manufacturers, but not for their attempt to delay the introduction of WLTP and more realistic estimates of miles per gallon and emissions.  There have been great improvements in energy efficiency of private cars over the past couple of decades, as engines have been designed to burn more leanly, aerodynamics have been improved and weight has been reduced by the introduction of more plastics and composite materials.  And if moving to a new calculation basis means that the EU's targets, set using the old method, are unachievable in the timescale, then maybe the targets should be adjusted to match any adjustment between the old NEDC and newer WLTP methods.  But consumers should demand more accurate and realistic estimates of typical fuel consumption, rather than being given increasingly unrealistic ones.

This is important because comparisons are not made between cars, but between cars and other forms of transport.  If my official consumption implies lower CO₂ emissions for driving between London and Manchester than taking the train (which it does), I may well end up making a misguided choice if I want to minimise carbon emissions.  (And of course the official train consumption is not the marginal emission from my joining an existing train, but the average emissions across all passengers, but that's another story).  It also distorts comparisons between figures for fossil fuelled cars (like mine) and electric vehicles, not to mention my trusty bicycle…

Moreover, as the gap between official and typical miles per gallon has now grown so large (some commentators estimate that it has doubled in the last 7 years²) it risks bring the whole concept of an energy label into disrepute. If you can't believe car labels, why should you believe those on fridges or homes?  (And yes, I know that there is also a well known performance gap on homes in particular, but we can at least explain most of the difference from lifestyle choices. It's different with cars as we don't choose to drive at 30mph in top gear with the windows taped up…)

So the car manufacturers should get real and give us real estimates of fuel consumption and CO₂ emissions.  And who knows, in a future blog, I may even be able to claim that I have bettered the official consumption by 10%!

¹ The UK average figure, based on retail fuel sales into the domestic market of 27.4mn tonnes of retail motor fuel (approx. 7.02 billion gallons) and DfT estimates of 242.3 billion miles driven in 2013 works out at an unimpressive 34.5mpg. However this is about 4% better than the equivalent figure for 2008, showing that there has been some real improvement, bearing in mind that almost two thirds of the cars on the road today were also on the road five years earlier; it also includes some non-passenger vehicles when they refuel through retail outlets.

² The ICCT report says that "the gap was especially pronounced after 2007–2008, when a number of European Union Member States switched to a CO₂-based vehicle taxation system and a mandatory EU CO₂ regulation for new cars was introduced."

Who dunnit? How to attribute CO2 emissions between nations

In my last blog, I referred to the relative simplicity of calculating an (approximate) carbon footprint.  Of course there's a lot of mystique around it (and an increasing number of relatively well-paid experts), but the fundamentals are not exactly rocket science.  Maybe some of the solutions should be kept equally simple and not made overly complex.  So if we can calculate our footprint here and now, perhaps we can also travel back in time and find out how much we have been responsible for historically?  This is not just a matter of academic interest, as developing nations contend that those that have been industrialised for longer periods have been greater contributors to the problem, and so should bear more of the burden in reducing future emissions and mitigating damage caused by past emissions.

There have been a number of attempts to do just this, and work out the share of cumulative greenhouse gas emissions attributable to each country.  It's far from being an exact science, as there are inevitably gaps in data and some pretty broad assumptions need to be made, but it's still - in my view - a worthwhile exercise.

The latest estimates can be found in Environmental Research Letters, an open access academic journal published by IOPscience.  As with personal or corporate footprinting, the key decisions are around boundaries and scope.  The boundaries are quite simple - nation states - but have a time factor as well: in this case going back to 1800 as being roughly the start of the industrial revolution, when coal began to display wood (and to a lesser extent wind or water power) as the main source of energy.  Pre-1800 use of coal was globally so low as to be lost in the rounding errors of carbon calculations.

This choice is however controversial, as early industrialised nations, such as the UK, were using fossil fuels in complete ignorance of any potential risks to the climate. It contrasts sharply with (say) the Sandbag Report on Sovereign Emissions (direct link to PDF report) which starts measurement at 1990, when the first IPCC report was published assessing the dangers of climate change.  Prior to that, most governments and citizens were unaware of the real risks from using fossil fuels (although the science had been understood for a while).

The Environmental Research Letters Report differs from most other estimates in a second important respect; as well as looking at emissions of the main greenhouse gases, it takes into account land use change and the effect of aerosols (not the ones used for deodorant, but a form of air pollution arising from sulphates emitted in burning fuels such as coal and that have a generally cooling effect on the climate.  These factors are quite significant and lead to some surprising countries having a net global cooling effect - including Chile and Kazakhstan.

The Report also converts cumulative tonnes of carbon dioxide equivalent (that snappy measuring units that geeks like myself love, but is hardly user friendly) into a contribution towards global temperature rises.  As you would expect, the top three contributors are the usual suspects: the USA, China and Russia, but Brazil slips in at number 4 and the European nations are headed by Germany, the UK and France at 6, 7 and 8.  On this metric, the USA is responsible for 0.151°C of global climate change, with China less than half that at 0.063°C.  Britain's 0.032°C  is actually double that of France, just one position below it in the league table.  And of the positive nations, Chile and Kazakhstan's reduction is less than 0.005°C:

Of course this is quite largely about population so the Environmental Research Letters Report goes one better, and relates to changes per billion inhabitants.  (It could do it per person, but that would give teeny numbers.)  This can be seen graphically below and has a surprising (to me) nation heading the table - the UK:

On this measure, red is bad (major contributor to global temperature change).  The UK has 0.54°C temperature rise per billion inhabitants, the USA 0.51°C, with Canada, Russia and Germany filling out the top five places.  China and India are near the bottom with around 0.04°C.  It should be added, that the report's authors only consider the top 20 emitters in this table, so although India is listed 20th on a per capita basis, it would be a lot lower if other countries were included.  It's also likely that the UK would lose its top spot in this "naughty league" to a smaller energy intensive user, such as Luxembourg or even Qatar or United Arab Emirates, which although they have only become large users of energy in relatively recent periods, are among the very largest users today.

So is this a fair measure?  I'm inclined to say "no", for several reasons.  Firstly, it's a little unfair to blame us for actions taken in complete scientific ignorance - I might not start the clock as late as Sandbag's 1990 baseline (as I personally was well aware of the likely problem in the late 1980s, and indeed so was Mrs Thatcher).  Maybe we should look at a weighted emissions, with 1800-1980 ones less culpable than more recent ones.  Secondly, the method looks only at direct origins of emissions, and ignores the fact that many of China's emissions (for example) may be attributed to Western demand for cheap goods, sometimes manufactured to less environmentally exacting standards.  Thirdly, there is always a problem of blaming children for the sins of their fathers; we should be judged on our current efforts to minimise emissions more than on what has gone before.  And at a national level, should recent immigrants be penalised for what long-standing residents have done?  (Even someone as apparently English as I am can point to a great-grandfather who immigrated from Ireland around a century ago, although at the time Ireland was part of the UK, too...)

But, even if it's not quite fair, it is still a useful exercise to help us think about long term responsibility.  And this doesn't just mean looking backwards at what our parents did, but also the responsibility that we have to future generations not to trash the world that they will be inheriting.

Calculating Carbon Footprints

Moving home often gives us a chance to take stock and think about all the changes since we first set foot in the old home. Moving websites can offer a similar opportunity for reflection, so as I have just moved the Simple Carbon Calculator (www.carbon-calculator.org.uk) I thought I would reflect on changes in that field.

By way of background, this Carbon Calculator (and there are others, I admit) has its origins as a challenge to myself and to support those in the Energy Efficiency Accreditation Scheme. Back in 2001, the UK's Department of Food and Rural Affairs (Defra) had not long published its first guidance to companies on calculating and reporting carbon dioxide (CO₂)emissions. Meanwhile, I had been tinkering with websites, and rather fancied seeing if I could convert their guidance into a simple calculator using a newfangled tool called JavaScript. So I took an open source bit of code and - necessarily - simplified Defra's factors a little to produce a basic calculator that you could enter energy use in normal units (kWh, litres, tonnes or other everyday values) and end up with a CO₂ value compliant with Defra's numbers.

Over the years, both Defra and I (quite independently, I must add) have enhanced the tools. But as Defra's has become ever more complex with over 4,000 conversion factors at the last count, I have tried to keep mine...simple. That's not to say that it's not useful; I believe that over 90% of households or companies could use the Simple Carbon Calculator to calculate their footprint within 5 minutes (assuming they had their energy consumption data to hand). And Defra's guidance notes and tables, along with 50 pages of assumptions are always available for the other 10%. (Incidentally the background paper, written by Ricardo-AEA is fascinating for use carbon nerds, but lacks the actual factors deduced from their discussions.)

This leads to a key point: calculating a footprint need not be terribly complicated; it's just a question of (a) having all the right data to hand and (b) knowing which are the right factors to use - and the aim of the Simple Carbon Calculator was to at least partly meet the second bit.

At the start, though, I said I would reflect on the changes to the actual calculation, rather than to website techniques which have rendered my old JavaScript "not modern enough" to stay on the previous host site.

First and foremost, the electricity factors have changed conceptually, twice, over the past12 years. When first created Defra thought it was best to use a marginal factor - ie. the emissions associated with generating an extra unit of electricity. In the UK, this was assumed to be electricity from a combined cycle gas turbine (CCGT) as they could be switched on and off most easily (try doing the same with a nuclear power plant...) However CCGT emissions (which were fixed for several years at 0.43kgCO₂/kWh) tend to be lower than average UK emissions (which included older gas stations and coal). So although it might be fine for a company or person at the margin, if you started adding up emissions from everyone calculated on this basis, you severely underestimated total emissions.

Recognising this problem, in the mid-2000s Defra moved to a five year rolling average. This captured longer term trends and wasn't unduly buffeted by abnormal power stations (such as nuclear power stations breaking down, which they seemed to have a distressing tendency to do). However over the past few years this has tended to lead to the opposite error, as coal power plants were mothballed and new zero energy generation - especially from offshore wind - has come on stream.

So, for 2013, we have all moved onto a prior year basis, on the grounds that the generation mix last year is probably the best indicator of what it will be this year. This has meant restating prior years (and miraculously losing emissions for the average user), but is probably the correct answer intellectually, unless someone can develop a 12 month forward weather forecast to estimate future wind energy production! However, we may find the downward trend reversing as US shale gas depressing the demand (and hence global price) for US coal, leading to more imports into Europe for power generation.

As you might expect, emissions for fuels (both gaseous and liquid) have tended to be less variable. However even there we find some trends emerging over the last 12 years. Natural gas, which once came almost wholly from the North Sea, is now increasingly coming in by ship from North Africa as LNG (Liquid Natural Gas) - as much as 20% in recent years. And although the Simple Carbon Calculator is designed for Scope 1/Scope 2 emissions (not full "Well to wheel"), Defra's factors do recognise the much larger carbon footprint of LNG.

Road fuels have also changed. Partly as a result of the EU biofuels directive, both diesel and petrol have a small biofuel component, and this has led to a slight drop in the carbon intensity of the fuel, as carbon from renewable sources is not included. That's not to say that biodiesel or bioethanol have anything like a zero carbon footprint; just that it's a bit lower than the equivalent fossil fuels.

Emissions from aviation are a great concern, as the fastest growing source globally. We have always known that the effects of planes flying at high altitudes was not just as simple as their CO₂ emissions, but that there were other effects, such as vapour in contrails that also exacerbated climate change. Well, finally this year Defra has accepted the arguments and included an uplift for "radiative forcing". Of course this means that for a typical middle class household flights are suddenly a much larger component of their carbon footprint...

As the calculator has grown in popularity I have added refinements and extra categories, while keeping to the concept of keeping everything on a single easy to use page. This year's enhancements included a much wider variety of default vehicles for those who know the approximate distances driven, but don't have records of fuel purchased. And, as an antidote to higher flight emissions, I have added Eurostar emissions - although these always seem unnaturally low as they are largely based on purchases of French nuclear electricity, and hurtling across Northern France at 300km/h may not be wholly environmentally benign!

So if this has whetted your appetite to find out your own footprint, I ought to tell you where the calculator has moved to. It's still at www.carbon-calculator.org.uk (and don't forget that hyphen), and may also be returning to its old host if I can negotiate with the new style gurus. Or it may be demolished and replaced with something even better, though perhaps not quite so simple to use.

Mrs Thatcher and Global Warming

I didn't vote for Mrs Thatcher. This is not just the slogan that launched a million tee-shirts but, in my case, absolutely true, even though I was old enough to vote for her Conservative Party. But this short blog entry, written the day after she died, is neither an attempt to hurl abuse at her nor a recognition that some – but not all – of the things that she did (and which I may have opposed at the time) were probably necessary to move the UK out of its stupor in the 1970s. Instead this will focus on one facet that has gone almost unremarked in the obituaries today: Mrs Thatcher was the first major Western leader to "get" Climate Change.

Trained as a research chemist at Oxford, Mrs Thatcher was proud to undertake a dispassionate analysis of the facts placed before her; this sometimes led her to intellectually appealing but socially divisive (and ultimately foolish) policies. But when presented with the relatively immature findings on the science behind climate change (still then known as global warming) she understood that this was an existential threat – more dangerous for the UK, even, than the European Union!

As far back as September 1988 she said in a speech to the Royal Society:

For generations, we have assumed that the efforts of mankind would leave the fundamental equilibrium of the world's systems and atmosphere stable. But it is possible that with all these enormous changes (population, agricultural, use of fossil fuels) concentrated into such a short period of time, we have unwittingly begun a massive experiment with the system of this planet itself.

This was later emphasised when she told the party conference:

The core of Tory philosophy and for the case for protecting the environment are the same. No generation has a freehold on this earth. All we have is a life tenancy—with a full repairing lease. This Government intends to meet the terms of that lease in full.

And by 1990 she was confident enough to say:

The danger of global warming is as yet unseen, but real enough for us to make changes and sacrifices, so that we do not live at the expense of future generations. … The need for more research should not be an excuse for delaying much needed action now.

This led to an early lead by the UK Government in taking measures to combat climate change and a broadly bipartisan attitude to the subject. Sadly the early lead has gone, and the UK is not doing much better than most of its peers in the move towards a lower carbon economy, and certainly behind that other great nation led by a right of centre female chemist – Germany under Angela Merkel. And many of Mrs Thatcher's successors in the Conservative Party would do well to heed those early words spoken almost 25 years ago – especially the UK's current Prime Minister who should note that her words were supported by action as national and international levels.

No longer Beyond Petroleum?

BP has indicated that it is looking to sell its US wind farms, at a possible loss of over $2 billion.  With this move, BP will once again be focused almost exclusively on petroleum ending the ground-breaking diversification into alternative energy under the leadership of Lord (John) Browne.  The vision of forming a company that provided the energy its customers needed to power their lives, but from a mix of increasingly low carbon sources encapsulated in the "Beyond Petroleum" slogan has long disappeared.  Of course, the strapline hadn't really been used for several years, and was being downplayed even before Lord Browne left the company in 2007.

Just over a decade ago, around the time of the BP-Amoco merger, BP looked as if it might become the first of the oil majors to diversify away from fossil fuels, and address the need to create a lower carbon economy.  Throughout the 1990s, BP was one of the leaders in solar cells and Amoco – through its Solarex subsidiary – was a large player in the growing US market.  BP exemplified this by adding solar panels to the canopies of many of its Connect filling stations and prominently displaying the amount of carbon-free energy generated.  After the merger with Amoco, in 2000 the company also adopted a new "helios" logo to replace the shield that had been used for over 60 years: this could be seen as signifying solar energy, or crops such as sunflowers.

So what went wrong and why were the wind farms such a poor investment?  BP's investment in US wind has suffered from two factors outside its control and largely unpredictable. The first is that despite high oil prices, other energy prices have not risen as much as anticipated, most recently due to the discovery of how to extract vast quantities of cheap gas from US shale formations.  This has had a knock-on effect on electricity prices, making renewable energy even less competitive on purely financial grounds.  And though Lord Browne knew that climate change should have led to an effective carbon tax, this has never been introduced into the US, keeping conventional electricity more competitive.  Despite the low prices for renewably generated energy, the cost of new wind turbines has fallen faster than anyone foresaw due to over-capacity among Chinese manufacturers.  This has had a knock-on effect on asset valuations for existing wind farms; it is often cheaper to build a new one than it would be to take on an old one at its depreciated value.  (A similar Chinese effect has affected solar, contributing to BP's exit from that renewable after more than 40 years at the end of 2011.)

BP has a third factor, unique to the company – a need to raise capital to fund the clean up and fines after the Macondo disaster.  Inevitably this has made it focus on non-core assets that can be sold – and wind farms, often held in joint ventures – were an obvious candidate. 

Despite this, BP has not totally abandoned alternative energy.  For the time being it remains a major player in liquid biofuels, especially in the USA where it is still named by Biofuels Digest (alongside Shell, but no other petroleum companies) as one of the 10 leaders in the field.  Of course this is an area much closer to BP's traditional road fuels business, and one where its lower cost of capital than smaller start-ups can still give it a competitive advantage.

But I for one will be sad to see the end of the idea of BP as a truly integrated energy company, investing in new cleaner forms of energy, with the hope that it might in our lifetimes achieve what we all find so hard to do: it might really have moved Beyond Petroleum.

Where's that gas coming from?

Britain is an island of coal set in a sea of oil and gas

The sentiment above has driven much of the UK's energy policy over the past 40 years, since North Sea gas first started flowing at the end of the 1960s. But no more; Britain became a net importer of energy in 2011 and its conventional gas reserves are drying up alarmingly fast. Data from DECC, the Department of Energy & Climate Change shows that production in 2011 (the last available full year) was 21% lower than in 2010, and that for the first three quarters of 2012 shows a continuing decline. So where is (or should) the gas be coming from?

Oddly, it is largely from the near continent, with over 50% of gas imports from the Norwegian North Sea, and almost 15% from Belgium and the Netherlands (although some of this may ultimately have come from Russia). The balance of around a third is from liquified natural gas (LNG) and, perhaps surprisingly, this has been declining. Energy flows are always difficult to analyse, but it appears that higher demand for gas in Asia has raised prices in Qatar, which in 2010 was the largest single supplier of LNG into the UK, using ships that the one shown here.

ShipSpotting.com

© Knut Helge Schistad

Britain continues to get LNG from North Africa - notwithstanding recent difficulties in Algeria - as the recession in Southern Europe reduces demand there.

In one sense this is to be welcomed; LNG has significantly higher emissions than piped natural gas, largely due to the energy used in the compression of the gas (but also due to some needed for decompression, and the fuel oil used by ships bringing the LNG to the UK from Qatar). But it also shows a risk: when a Norwegian pipeline (Langeled) was recently out of commission due to a power cut, prices spiked and the UK was temporarily suffering a significant shortfall of supply. In the third quarter of 2012 this one pipeline provided 33.6TWh of gas, compared to total national consumption of 65.5TWh. As always, diversity of supply is important for security, especially as Norwegian production has also peaked.

So is shale gas the answer? Almost certainly not in the UK for other environmental considerations, although the development of US shale resources has lowered global gas supplies as they too are importing less LNG. Going back to coal is not an option either, for both CO2 and practical reasons (although it is sad that an underground fire has led to the loss of the UK's largest remaining coal mine). I am afraid that the real answer in the longer term is that we still need to cut demand, through greater energy efficiency, and to support this with other offshore technologies - wind, tide and wave. So finally we may one day be able to say:

Britain is an island of efficiency set in a sea of wind and waves