The climate science isn’t “in”

aka back and better than the same as ever

MK has been dormant since June 2013 — almost 2 years! It’s been a while since I wrote a bona fide blog post, but I miss doing that, so I figured I would, and on one of my favourite old topics (see HERE). This one is dedicated to my handfuls upon handfuls of readers.

I believe in climate change. I also am not all that bothered by it.

That attitude seems to raise a few eyebrows. Most people assume that if you believe in climate change, then you must see a desperate need to “take action” against it and, conversely, if you do not care much about climate change, then you are obviously one of those “climate change deniers” (a term that’s a little too close to “Holocaust denier” for my liking).

I don’t fall into either category. My thoughts can be encapsulated quite neatly in three points (and I think I may be paraphrasing John Humphreys):

1. Is the climate changing? Yes.
2. Are humans causing that? Probably.
3. Is it as bad as we think? No.
4. Does it warrant drastic government intervention? Almost definitely not.

As points 1 and 2 have been adequately canvassed elsewhere, and point 4 follows from point 3, I’ll concentrate on point 3 for the balance of this post. Before I do that, I should give this qualification: I’ll admit that I can’t claim to be an expert on the subject, but I do have a statistics major, so I am at least somewhat qualified to comment on the research findings that people like to throw around. And I have read the most authoritative material out there, like the Intergovernmental Panel on Climate Change (IPCC) reports and the major Royal Society reviews (see HERE).

So with the power of that limited knowledge and drawing on my hours of research, here is what i think:

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The future hasn’t happened yet

People have been predicting the end of the world for as long as there have been people, and that includes in this “enlightened” age of “science” that we now live in. Yet the doomsayers have been proven wrong each time.

The problem with predicting the future is that it hasn’t happened yet. That may seem obvious, but it is constantly overlooked by “scientists” the world over. The standard way of predicting the future using maths, “time series analysis”, boils down to this: take what has happened in the past, figure out what the average was, and assume that the future will be the same.

This might seem intuitive — after all, the best indication of what will happen in the future that we have is what has already happened — but it is in fact an extremely flawed way of looking at the world. The best and most well known critic of the formula is probably Nassim Taleb. He makes the following criticisms:

   1. Outliers

The past is peppered with what Taleb calls “Black Swan” events and what everyone else calls “outliers”. Outliers are rare events that are different to all other events, and therefore cannot be predicted. It is impossible to predict the unpredictable, therefore any statistical projections will invariably miss the outliers, especially if it is predicting the future based on the past average.

This results in things like financial analysts missing the Global Financial Crisis (bad outlier), or Thomas Malthus predicting that all the food would run out and missing the productivity improvements of the industrial revolution (good outlier, back in Malthus’s time).

   2. Knowing it all

Time series predictions involve a degree of hubris. They assume that we understand the past and why everything in the past has happened, and can confidently reduce the infinitely complex universe into a few variables that will inevitably explain anything, and so if we know how one or two of these will behave then we can comfortably predict everything else.

We give ourselves too much credit. Our actual understanding of complex systems is much weaker than we’d like to think. “Experts” modelling complex systems mathematically are constantly even getting the past wrong, so how anyone thinks they can predict the future with much accuracy I have no idea.

   3. Proxies and correlations

Some things are easier to measure than others. Whenever an analysts wants to measure something complex that cannot really be measured they will use a “proxy variable” that would generally correlate with the unmeasurable variable. For example, it is not possible to measure “health”, so if you want to measure the health of a population, you might measure their average life expectancy. After all, if people tend to live longer, you would assume that they are healthier.

Makes sense right? Well maybe. One problem is that you might be missing some other variables that are affecting the situation. For example, maybe your “unhealthy” group are actually super fit and super healthy, but have an unfortunate habit of dying in car crashes. So perhaps life expectancy doesn’t correlate as well with health as you would expect.

But assume that the two variables correlate perfectly. That itself may be a problem.

Take this example: Christian Rudder from online dating website OK Cupid has found that regardless of gender, OK Cupid users who like the taste of beer tend to prefer having sex on the first date. That statistic is quite amusing, but no one would seriously suggest that this means that drinking beer changes the way someone thinks about sex, right?

Wrong. “Scientists” do that all the time, and the journalists who report their findings do it even more.

That example makes it especially obvious that the correlation between beer and sex is not causative. Liking beer does not cause someone to want to have sex on a first date, and wanting sex on a first date does not cause someone to like the taste of beer. More likely, there is a third factor at play that causes a lot of people who like beer to also want sex on a first date — probably youth culture or something. Or it could simply be a coincidence.

But that doesn’t stop people saying that hormone replacement therapy can help stop heart disease.

   

4. The Wayne Swan error*

Ever wondered why the government’s budget always seems to blow out? Here’s why. Say the government projects that next year’s budget will balance, with a 2% margin of error and 95% confidence. This means that there is a 95% chance that budget will be within 2% of a balanced budget (a pipe dream right now, I know).

In reality, it is almost impossible that the budget will come in below the projection — as once allocated money to spend, very few (if any) government departments will choose not spend it. On the other hand, it is quite likely that the budget will blow out, as government departments have many unforeseen expenses. So there is not so much a 95% chance that the budget will be within 2% of balanced, there is a 95% chance that there will be a deficit of 2% or less, and a 5% chance of a deficit of over 2%. I like to call that the “Wayne Swan error”, after the former Australian Treasurer who seemed to manage to blow out the budget every year that he was in office (it is also fast becoming the “Joe Hockey error”).

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Getting to the point

The reason I don’t think that climate change is so bad is that the predictions that I have seen of the impact of climate change fall into all of the above traps, along with an unhealthy dose of confirmation bias. Arctic sea ice at record lows? We’re doomed! Arctic sea ice at record highs? We’re still doomed!

Remember Professor Tim Flannery? The “climate expert” who predicted unending drought when we had a drought, then unending floods when we had floods? My point exactly.

Even the most respectable science journals make outlandish predictions about mass-extinctions, rising sea levels, and economic misery based on people trying to predict the future from past averages and assuming that they understand complex systems.

Their predictions are constantly wrong. It turns out that nature is a lot more robust than we give it credit for. We forget that life on Earth has not been eliminated despite ice ages, periods of warming, super-volcanoes, floods, hurricanes, earthquakes, and everything else that nature throws at us. I seriously doubt that the atmosphere warming a couple of degrees will mean the end of the world as we know it.

Further, as a result of nature being more robust than we think, as well as humanity’s propensity for alarmism, climate scientists’ projections are subject to the “Wayne Swan error”-style second order effects that I was talking about earlier.

Scientific papers wrongly predicting the end of the world are much more likely to be published than ones predicting that everything will carry on the way it has in the past, and are much more likely to attract attention once published. Also, scientists are more likely to miss mitigating factors than exacerbating ones, and therefore overestimate both global warming and its effects. We know what causes warming — greenhouse gas levels — but not what mitigates it. Accordingly, our measurements of warming are biased towards warmer rather than cooler, and our projections are biased towards “worst case” rather than “best case” scenarios.

The biggest problem with the way we think about projections is that people are not held to account for getting it wrong. Climate forecasts made 20 years ago have proven woefully inaccurate, yet they are somehow touted as being correct. A couple of years ago, the IPCC released a report saying how accurate their 1990 projections were, and headlines around the world said “climate predictions come true”, when what had in fact happened was that the world had consistently warmed more slowly than the IPCC’s projections, but (big woop!) the warming had been within the range that the IPCC predicted. See this graph:

Now, remember that the predictions were made in 1990. Notice how the model “predicts” that temperatures before 1990 (which would have been factored into the model) would be roughly evenly distributed around the middle line, but that temperatures since 1990 (which obviously were not known when the projections were made) have been consistently below that line.

Sure enough, according to the IPCC’s projections, the world should have warmed about 0.55 degrees between 1990 and 2010. It actually warmed 0.39 degrees. That’s 30% less than projected — a pretty dismal result really. Although I’ll admit that sea levels seem to have been rising at the top end of what was projected, despite the rise in temperature being lower than projected.

Anyway, the point is that a PhD in climate science is about as useful as a crystal ball and a red and white tent when it comes to making soothsayers. Meanwhile, both humanity and nature constantly surprise with their ability to not be destroyed by whatever calamity we are predicting at the time.

All this is not to say that we shouldn’t be reducing our CO2 emissions and switching to renewable energy. But a carbon tax? No.

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* Taleb makes some other criticisms which are a lot more technical and would be lost on most readers without a mathematical background. I encourage everyone to read his books, where he explains his ideas in a very accessible way.

For people who do understand this kind of thing, the Wayne Swan error is this: Most models use a 95% confidence level to compute “statistically significant” findings. If you’re lucky this will be at 99%. Not only does this a priori overlook the 5% or 1% of outliers which can have a far more significant impact on whatever the model is measuring than the 95-99% of “normal” cases, another common oversight make it likely that the confidence level is substantially underestimated: namely the assumption that the error terms are random. Often, the error terms are actually non-linear, which adds unseen biases to the model.

Reshuffling the gargantuan cabinet

Something seemed curious to me, looking at the list of new ministers in Australia’s recent government reshuffle:

Julia Gillard loads up senior ministers in her sixth reshuffle | The Australian.

The Prime Minister used her sixth ministerial reshuffle to merge the Department of Climate Change with the Department of Industry, creating a new Department of Industry, Innovation, Climate Change, Science, Research and Tertiary Education.

Dr Emerson has been appointed Minister for Tertiary Education, Skills, Science and Research – the role relinquished by Mr Bowen – while continuing as Minister for Trade and Minister Assisting the Prime Minister on Asian Century Policy.

Mr Albanese, a Rudd supporter who escaped demotion after last week’s events, has taken on Mr Crean’s former portfolio of regional development and local government, while remaining Minister for Infrastructure and Transport and Leader of the House.

Mr Gray, a West Australian with close mining industry links, has been awarded Martin Ferguson’s old resources and energy and tourism portfolios. He also takes Mr Bowen’s vacated small business ministry.

Mr Gray’s special minister of state responsibilities go to Attorney-General Mark Dreyfus.

Mr Clare, the Minister for Home Affairs and Justice, becomes a full cabinet member with his current roles. […]

Mr Albanese will be supported by Victorian MP Catherine King, who has been elevated to the outer ministry as Minister for Regional Services, Local Communities and Territories, and as Minister for Road Safety.

Gillard supporter and so-called “faceless man” Don Farrell has been promoted to the ministry as Minister for Science and Research, while fellow backer Sharon Bird becomes Minister for Higher Education and Skills.

Queenslander Jan McLucas steps into Kim Carr’s role as Minister for Human Services following his resignation last week.

Environment Minister Tony Burke becomes Arts Minister in addition to his current responsibilities, taking on Mr Crean’s other portfolio following his sacking last week.

Ms Gillard also appointed a number of parliamentary secretaries to assist ministers with heavy workloads…

I’m not going to even bother getting into the Parl Secs. Let’s have a look at that ministry.

Apparently the departments of Industry and Innovation are different from Small Business. We also have a Department of Higher Education and Skills, and a Department of Science and Research, both of which are different from the new Department of Industry, Innovation, Climate Change, Science, Research and Tertiary Education.

Oh, and apparently that mammoth “Industry, Innovation, Climate Change, etc” portfolio also does not encompass Climate Change, which needs its own separate department as well. Or, for that matter, Resources and Energy.

Then there’s the fact that “Human Services” and “Regional Services” are different — perhaps because regional Australians are not human?

One would think that there is some doubling-up going on between all of these public service departments. Perhaps the government’s failure to deliver a budget surplus, despite record terms of trade, would have something to do with this gargantuan bureaucracy that they have been constructing?

Nah, couldn’t be.

I just thought it was cold out

Apparently that means I’m politically conservative. Go figure.

Politics influences beliefs about weather and comfort and air conditioning. – Slate Magazine.

Yes it would, the study found. So much so, in fact, that the people surveyed all but ignored their actual experience. No matter what the weather records showed for a given neighborhood (despite the global trend, it had gotten colder in some places and warmer in others), conservatives and liberals fell into the same two camps. The former said that temperatures were decreasing or had stayed the same, and the latter claimed they were going up. “Actual temperature deviations proved to be a relatively weak predictor of perceptions,” wrote the authors. (Hat tip to Ars Technica for finding the study.)

This is how a climate change article is done: take note

As you may have guessed by the infrequent posts recently, for a number of reasons I have not had the time to read/write like I usually would (and won’t for a while). Catching-up on the New Yorker from two weeks ago, I just read this article by Michael Specter on geoengineering.

I was going to provide excerpts and commentary, like I usually would, but that really wouldn’t do this article justice. Specter manages to succinctly cover almost every relevant piece of information about climate change: the history of the science, the current state of knowledge, the different options available, the possible economic costs, the political will etc.

The article shows that there is potential for catastrophe and there are a lot of horrible-sounding predictions, but these are all unreliable and we have historically been very inaccurate when trying to predict weather patterns. Similarly, the most coveted option (of cutting carbon emissions entirely) is completely unrealistic and probably more insane than the geoengineering options described in the article, all of which are a insane to some extent.

The one point that I want to concentrate on came close to the end, it concerns the lack of an international legal system to deal with activity that alters the climate. I have not finished processing the repercussions of this, but I will probably write a post once I have thought it all through.

In the meantime, I strongly recommend clicking through and reading the full article. It makes Mark Latham’s attempt look like a primary school science project (if it didn’t look like that already, that is).

Can Geoengineering Solve Global Warming? : The New Yorker.

The most environmentally sound approach to geoengineering is the least palatable politically. “If it becomes necessary to ring the planet with sulfates, why would you do that all at once?’’ Ken Caldeira asked. “If the total amount of climate change that occurs could be neutralized by one Mt. Pinatubo, then doesn’t it make sense to add one per cent this year, two per cent next year, and three per cent the year after that?’’ he said. “Ramp it up slowly, throughout the century, and that way we can monitor what is happening. If we see something at one per cent that seems dangerous, we can easily dial it back. But who is going to do that when we don’t have a visible crisis? Which politician in which country?’’

Unfortunately, the least risky approach politically is also the most dangerous: do nothing until the world is faced with a cataclysm and then slip into a frenzied crisis mode. The political implications of any such action would be impossible to overstate. What would happen, for example, if one country decided to embark on such a program without the agreement of other countries? Or if industrialized nations agreed to inject sulfur particles into the stratosphere and accidentally set off a climate emergency that caused drought in China, India, or Africa?

“Let’s say the Chinese government decides their monsoon strength, upon which hundreds of millions of people rely for sustenance, is weakening,” Caldeira said. “They have reason to believe that making clouds right near the ocean might help, and they started to do that, and the Indians found out and believed—justifiably or not—that it would make their monsoon worse. What happens then? Where do we go to discuss that? We have no mechanism to settle that dispute.”

Science eh? Q and A tackles climate change without any, you know, scientists

Remember that Mark Latham article about listening to scientists that didn’t ask any scientists what they thought? Well, continuing this trend, for the ‘Climate Debate’ on Q and A tonight, the guests are:

Coming up | Q&A | ABC TV.

• Rebecca Huntley – social researcher and writer
• Nick Minchin – Former Liberal Minister
• Anna Rose – founder of the Australian Youth Climate Coalition
• Clive Palmer – mining magnate
• Dr Megan Clark – Chief Executive of the CSIRO

Megan Clark is the closest thing to a climate scientist there — but she’s a geologist/engineer-turned-businesswoman. She may have scientific credentials, but she is not an expert in atmospheric science. Otherwise, we have a social scientist, a politician, an NGO-worker and a billionaire mining magnate.

I cannot see this happening for any other scientific debate. Try and imagine if they had a show about whether black holes are real, but did not invite a single astro-physicist; or a show about evolution without a single biologist.

As I have argued before, the climate change debate has long-ago ceased to be remotely about science. There is nothing scientific happening here whatsoever.

I’m sick to death of being preached at about “listening to scientists” by people who couldn’t tell you what “GCM” even stands for, let-alone how a GCM is constructed.

But then, “the science is in”, no?

Two things I learnt from Mark Latham today

Number one: being the son of Holocaust survivors makes you left wing.

Climate change denial and the suburbs.

Manne grew up in the shadow of the Holocaust, having lost his grandparents to the Nazi horror. This linked him instinctively to the politics of the left. After the war, however, when other young left activists were blindly defending Stalin and Mao, Manne looked to the evidence and saw evil – thus commencing his pilgrimage to the anti-communist right. Fifteen years ago he broke from this neoconservative cadre on another matter of historical record, the tragedy of the stolen generations.

Number two: you can write a 2,000 word essay about “listening to science” without quoting a single scientist or giving a single piece of scientific information.

Confident in their professional training and achievements, middle-class citizens are prepared to challenge the academic elites. Successful people in the suburbs see themselves as in-tune with the real world, while scientists are absorbed by theoretical abstractions. In the Information Age, it seems, everyone is a master of every subject they hear something about.

This phenomenon reminds me of the Isaac Asimov novels I read as a teenager: a sci-fi vision whereby society is so well educated, with so much exposure to information, that science has lost its place in the pecking order of respect.

The irony, it’s killing me…

Peak oil is inevitable

And the free market is bringing it. Nuts to you, Bob Brown.

Amory Lovins in Foreign Affairs:

A Farewell to Fossil Fuels | Foreign Affairs.

U.S. gasoline demand peaked in 2007; the oil use of the countries of the Organization for Economic Cooperation and Development peaked in 2005. With China and India pursuing efficient and electric vehicles, Deutsche Bank forecast in 2009 that world oil use could begin to decline after 2016. In fact, the world is nearing “peak oil” — not in supply but in demand. Oil is simply becoming uncompetitive even at low prices before it becomes unavailable even at high prices.

I also want to throw in this story, for good measure:

In 1850, most U.S. homes used whale-oil lamps, and whaling was the country’s fifth-biggest industry. But as whale populations dwindled, the price of whale oil rose, so between 1850 and 1859, coal-derived synthetic fuels grabbed more than five-sixths of the lighting market. In 1859, Edwin Drake struck oil, and kerosene, thanks to generous tax breaks, soon took over. Whalers, astounded that they had run out of customers before they ran out of whales, begged for federal subsidies on national security grounds, but Thomas Edison’s 1879 invention of electric lighting snuffed out their industry. Whales had been accidentally saved by technological innovators and profit-maximizing capitalists.

Energy efficiency is strategically important, but it also saves money. There is no need for Government to start saving the world here, human innovation is doing it just fine, thank you.

In defence of skepticism on climate change

Reviewing the “Heartland affair”, Robert Murphy notes how one climate scientist did not think that the actual evidence against Heartland was enough and decided to forge a more “damning” document; and how gleefully the rest of the climate change movement began adopting this clearly forged document with no skepticism whatsoever:

Diminished Climate Alarmism: Lessons from L’Affair Heartland — MasterResource

Now to be sure, climate science isn’t the same thing as politics and the blogosphere. Just because these climate alarmists showed ridiculously bad judgment when it came to the Heartland affair, doesn’t necessarily mean that they are wrong about the trajectory of global temperatures in the absence of mitigation strategies.

However, I do think this episode—and the reaction of the skeptic community during Climategate—are quite illustrative of the two camps’ approaches to the actual science. Back when the Climategate emails were first spreading around the Internet, I distinctly remember many people in the comments at blogs such as ClimateAudit warning their peers by saying things like, “Guys, remember, we’re skeptics. This is too good to be true. Let’s not jump up and down on this, because it might be a trap to make us look gullible.”

In contrast, the major players on the other side—when Heartland was “caught” saying things that were far more absurd than what the Climategate emails revealed—jumped with glee. For example…

Walter Russell Mead posits his analysis of the incentives leading to distortions in the climate debate:

How Green Gullibility, Hyperpartisanship Are Wrecking The Climate Movement | Via Meadia.

• The climate movement’s proposals (above all, the global carbon treaty that in theory will subject the economic output of  every country on earth to global controls) are radical, costly and virtually certain to fail.
• To be enacted, these unpromising measures require an unprecedented degree of consensus, as every major country on earth would have to accept, ratify and then enforce the climate treaty the movement seeks.
• The climate movement must therefore be, in Dean Acheson’s words, “clearer than truth” in order to stampede public and elite opinion around the world into a unique and unparalleled act of global legislation.
• Because many in the climate movement believe that this treaty is literally a matter of life and death for the human race, the moral case both for stretching the evidence and attacking critics of that agenda as aggressively as possible looks strong to weak minds.
• The absence of any central authority or quality control in the climate movement (and the tendency of unbalanced foundation execs and direct mail contributors to provide greater support to those ready to take more aggressive action and espouse more alarming ideas) gives more radical and less responsible voices undue prominence and entangles the whole movement in dubious claims.
• The increasing obstacles encountered by such a poorly conceptualized and poorly advocated agenda cause the embittered and alarmed advocates to circle the wagons and become both more extreme in their rhetoric and less guarded in their claims when precisely the opposite approach would work better.

I must say that I have a lot of sympathy for this position, although I do not think the phenomenon is limited to the “the world is ending” side of the debate; the other side is just as irrational and just as selective in its facts/deliberately deceptive for policy reasons.

What we essentially have is a political debate posing as a scientific one. The best example of this is the fact that the most commonly cited reason to believe in the climate change alarm is the supposed “scientific consensus” shown through petitions like this one — the idea being that if 31,487 scientists agree with something, it can’t possibly be wrong.

The very idea makes a mockery of

Climate of fear pt 1

It’s not often that I’ve taken a request on Major Karnage, but in response to some criticism that I had of a rather inane rant about the carbon tax, I was asked what my stance is. I will, therefore, try to briefly explain the whole climate change debate from my perspective. The first post will deal with climate change in general, the second will deal with the carbon tax specifically.

The whole climate change debate really, at the end of the day, is about the science. What I find ironic/depressing is how so many people, the author of that post included, seem to take what is said about a “scientific consensus” at face value. On the other hand, the critics of climate change often seem to display an alarming degree of “confirmation bias” – lauding anyone that attacks climate science, no matter how dubious their credentials. I take the view that to be able to argue confidently on these kinds of issues, it is essential to actually understand the science – don’t take Gillard’s word for it or Abbott’s. In fact, don’t even take my word for it. I feel like the whole world is up-in-arms over this issue, yet the most vocal proponents of carbon taxes seem to have taken everything they know about climate science from an Al Gore documentary.

So what does the science say?

Before I start, just so everyone knows, I do have a science degree – meaning that I can read scientific articles and know what they’re on about, but I’m not exactly Stephen Hawking.

The best summary that I’ve seen was done by The Royal Society and can be downloaded HERE, while the best collection of graphs and pictures comes from NASA and can be downloaded HERE (look at the second half for the graphs). As the Royal Society report notes, there is a general (but not unanimous) agreement that the Earth’s surface temperature has increased over the last few decades and that CO2 levels have increased significantly as a result of human activity. Also, methane levels have increased, probably due to human activity but possibly due to other factors. There is proof that there is a “greenhouse effect”, in that these gases can trap solar energy in our atmosphere and so increase the temperature.

That said, the climate is extremely complex and there is a lot that is not yet known. Climate models are becoming more and more sophisticated, but they are still extremely simplistic and do not yet have the capability to include all of the variables that we know cause the climate to change. There are even some things that are very poorly understood, as well as a hell of a lot that we do not really consider. For instance, there is very limited understanding of natural “carbon capture” – where CO2 is stored in soil and plants – even though it is estimated that 50% of all human emissions are taken-up in this way. Also, temperature readings from more than 150 years ago are very inaccurate – they mostly rely on readings from gas bubbles trapped in glaciers. In the geological scheme of things like the climate, 150 years is nothing.

Finally, our attention spans are really too short for the whole debate. Climate change does not happen over days, months or even years – it happens over decades, centuries and millennia. A particularly cold winter, or even five winters, does not mean that the world is not warmer over a 20-year period. Similarly, a particularly warm 50 years may mean nothing over the course of a millenium.

The longer the period of time that you are looking at is, the clearer the trends will become. The graph above shows this – it is using the moving average over 5 years (red) and 11 years (blue). Compare that to the one below, which has one month and one year averages – this shows how it is possible to choose a time period that will show cooling, but this does not fit with the overall trend (as seen above).

The reality is that the climate is, incontrovertibly, getting warmer. There is not a lot more to say on the subject – people who refute this are either ignorant or dishonest. That said, there is a lot that “warmists” don’t like to talk about.

What we don’t talk about

There are also a lot of factors that affect the climate that no one in the debate seems to be really mentioning. Remember how greenhouse gasses trap sunlight that was reflected from the Earth? Well, as everyone who has worn a black suit on a hot day will know, dark colours absorb heat, whereas bright colours reflect it. This has a huge net effect on the environment – the more of the planet’s surface that is dark (i.e. rainforests, farmland, black rocks), the more energy is absorbed and vice versa. Because of this, clouds actually create a significant cooling effect, as does deforestation. However, water vapour in the atmosphere that does not form clouds acts as a greenhouse gas in fact, less water vapour in the atmosphere reduced global warming by 25% over the last decade. I’m waiting for a steam tax…

Another thing that causes global cooling is pollution. Yes, you read that right. There was no global warming for 100 years after the industrial revolution started, despite huge levels of CO2 emissions. Why is this? Well, pollution was a lot dirtier at the time – particles of soot and smoke prevented sunlight from reaching the planet’s surface. Similarly, volcanoes have found to have a significant cooling effect because of the ash emitted, as well as the sulphur dioxide (SO2) emitted high into the atmosphere.

This is even assuming that we know everything that causes global temperatures to change, which may well not be the case. The climate is thought to have changed significantly in the last 2,000 years – ancient writings sound like a hotter world than today, then there was a mini-ice age that ended somewhere around the 1500s. There is not, at this time, a causative link between emissions and warming. This means that we know that emissions have gone up and that, in theory, emissions cause warming; but we do not know for absolute sure that the one caused the other, it’s just a correlation.

In fact, we know that warming increases levels of CO2 . There are billions of tons of CO2 dissolved in water on the planet. CO2 is also what makes the bubbles in sparkling drinks. When you leave Coke in a warm place, the CO2 escapes and the drink becomes flat – the same phenomenon means that warmer oceans emit huge amounts of CO2 (are we going to start taxing the Tasman?)

Obviously, this post was just the – wait for it – tip of the iceberg. People spend their entire lives studying this stuff; I’ve spent a few hours reading some scientific journal articles and you just spent 10 mins reading a blog post. The take-home point point is this: nothing is certain. And arts students really need to stop lecturing me about “understanding the science”.

Stay tuned for Part 2, where I’ll talk more politics and less science.

Climate change cut and paste

From The Australian today. Some things it’s hard to argue with…

They know what you said, PM, they’ve read the transcript in Cut & Paste often enough | The Australian.

Refugee crisis! David Adam, The Guardian, 12 October, 2005:

Rising sea levels, desertification and shrinking freshwater supplies will create up to 50 million environmental refugees by 2010, experts warn today. “There are well-founded fears that the number of people fleeing untenable environmental conditions may grow exponentially as the world experiences the effects of climate change,” Dr Bogardi said. “This new category of refugee needs to find a place in international agreements. We need to better anticipate support requirements, similar to those of people fleeing other unviable situations.”

Or maybe not. Gavin Atkins, Asian Correspondent, April 11, 2011

In 2005, the United Nations Environment Program predicted that climate change would create 50 million climate refugees by 2010. These people, it was said, would flee a range of disasters, including sea-level rise, increases in the numbers and severity of hurricanes, and disruption to food production. A very cursory look at the first available evidence seems to show that the places identified by the UNEP as most at risk of having climate refugees are not only not losing people, they are actually among the fastest-growing regions in the world.