OneAndOneIs2

I see /. had one of it's periodic "Global warming is/isn't happening" debates last night. I missed it while it was happening - we were busy booking our two-week holiday in the States for October..

It's the usual tired old arguments yet again. I find most of the online debates - and not a little of the profesional news coverage - to be immensely annoying, for a number of reasons. Mostly, it's the total over-simplification of an enormously complex subject.

Firstly, there's this constant implication that the climate has a "default" state: that it should be stable and unchanging and the mere fact that temperatures and atmospheric composition are changing is proof of a massively damaged ecosystem.

I don't know where this comes from - maybe it's a lingering effect of the once-widespread Creation beliefs: The Earth was created perfect & any change is therefore bad. But it's not true: The Earth has never, at any time, had a stable & unchanging climate. The mere fact of climate change is not itself evidence of a problem. In fact, the single most worrying climate trend I can think of would be one that showed total stasis in the climate: The number of things that would have to go wrong for this to happen is unreal. Making the climate stand still is like trying to balance a pencil on its point: It might be possible in theory, but you'll never manage it in practice.

Secondly, leading on from the first point, is the absolute inattention that is given to the alternative to global warming. "We need to stop the planet heating up, because it'll cause storms and flooding and all kinds of terrible changes!" - Given that the Earth never remains stable, you have just two options: It's either getting hotter, or it's getting colder.

In fact, it's fair to say that the Earth has just two states: It is always either going into an ice age, or coming out of an ice age.

And if you think that global warming is bad because it causes sea level changes and bad weather, you have absolutely no idea what an ice age does to the climate. Polar ice melting and causing coastal flooding is bad, but glaciers levelling most of the world's landmass is worse. By all means, talk about slowing the warming, but stop talking about stopping it altogether: If it's not getting warmer, it's just going to get colder.

Thirdly, leading on from the first two, is the attitude that the mere fact of increasing global temperatures is proof that humans have caused unnatural climate changes, backed up by graphs that go back a few decades or centuries. This time period seems really impressive to short-lived animals like us, but the climate is a slower beast: Its heart beat is measured in millennia.

The last ice age was 10,000 years ago. The ice-age cycle has been on a 40,000 to 100,000 periodicity. Ice ages start fast & end slow: As the ice sheets expand, they reflect more sunlight and cause a decrease in temperature, leading to further ice formation.

Right now, today, at this very moment, we are still emerging from an ice age. Increasing temperatures is exactly what should be happening right now. Even if humanity had never existed, temperatures would be increasing on this planet today. The thing you need to prove if you want to show humans are having an effect on climate is not "Temperatures are going up", it's "Temperatures are going up more than they would be if we weren't here" - don't misrepresent natural changes as man-made. Goodness knows there's plenty of genuine man-made problems to shout about.

Fourthly is the massive exaggeration of Carbon Dioxide's role in the greenhouse effect. It beggars belief that people actually claim that CO2 is the gas responsible for most of the greenhouse effect.

Is it Hell: More than 90% of the greenhouse effect is generated by water vapour. The amount of the greenhouse effect generated by CO2 is almost trivial in comparison. It certainly is a greenhouse gas, but please, don't misrepresent it as the greenhouse gas. It just isn't.

Fifthly is the overwhelming ignorance of how CO2 is generated and removed. There is no greater example of this than the claim that "The rainforests are the lungs of the planet" - whomever came up with this one clearly has very little knowledge of basic plant and food chain biology.

Plants photosynthesize only during the day. At night, they respire: Plants actually consume Oxygen when photosynthesis can't occur.

Plants photosynthesize in order to generate hydrocarbons with which to fuel their growth. Plants that are not growing much are not photosynthesizing much. A grown tree that's just replacing the odd leaf here & there is doing very little to absorb carbon, compared to a sapling that's burning through the stuff as fast as it can to add wood to its trunk.

All the carbon that a plant absorbs gets released back into the environment during and after the plant's life: Animals eat the fruit & leaves. Animal droppings, dropped leaves, fallen branches & fruit, and ultimately the tree itself when it dies - they all rot and release the stored-up carbon.

So basically: A rainforest is full of trees that are barely growing, decomposing plant matter, and animals. All of which combines to mean that rainforests do pretty much nothing for the planet's CO2 levels. If they vanished overnight, we wouldn't suddenly asphyxiate.

That's not to say that burning huge swathes of them & dumping masses of carbon dioxide into the air at a vastly increased pace is a good idea. But "Burning the rainforests puts lots of Carbon dioxide into the atmosphere" is nothing like the same as "Most of the planet's Oxygen comes from the rainforests"

And it's evident in other places too: People talk about "getting rid" of carbon dioxide. I'd really rather you didn't, guys: Carbon dioxide is where Oxygen comes from. The best way to remove carbon dioxide from the atmosphere is to get it locked up in biomass: That's why paper from sustainable forests is such a great thing. The trees grow, converting Carbon dioxide to Oxygen in the process. Then the trees get turned into paper, locking the carbon safely away on bookshelves. Then you grow more trees, and the cycle repeats.

The important thing to remember about CO2 is it's a cycle: CO2 is produced, CO2 is consumed. And yet, the logic is alwaysstated as "There's more CO2 in the atmosphere, we must have caused it by using CO2-generating processes." Not once in all the literature have I ever seen any recognition of the fact that you could equally well conclude "There's more CO2 in the atmosphere, we must have caused it by destroying CO2 absorption processes." Through our farming, fishing, constructing, landscaping, and other such activities, we've had huge impacts on the whole ecosystem. Why does nobody ever pay any attention to them?

Where was I? Umm... sixthly(?) is the really annoying claim that the human impact on the climate is leading to an extinction rate that is higher than at any time since (or even including in some claims) the dinosaurs.

Bollocks. There are four very important numbers that this claim needs to back it up that we don't have.

Firstly, you need to know how many species existed just before dinosaurs got clobbered by the meteor or whatever it was. We don't know this: Fossilization just doesn't happen reliably enough for us to get that accurate a count.

Secondly, you need to know how fast the dinosaurs died out. We don't: Fossilization being rare strikes again. If you get one T.Rex fossil per half-million years (I believe it's about that number) you can't really see any difference between "It died out overnight" and "It died out over thousands of years"

Thirdly, you need to know how many species we have on the planet today. We don't: The difference between our lowest estimates and our highest estimates is more than an order of magnitude.

Fourthly, you need to know how many species are dying out. We don't. We only have very small surveys of what's changing in very small areas.

So given that we're lacking every single one of these numbers, just how can anyone claim that they know exactly what the extinction rate is, what is has been, and that it's faster now than it has been any other time?

Claim that species are being pushed into extinction, by all means: That's indisputable. But leave out the hype. If you say one thing that's patently untrue, why should anyone believe other things that you say?

Seventh: Be honest: Admit that some organisms benefit from the changes humans cause in the environment. "Cities are ecologically horrible places that have no plants and lots of machinery" may be true, but just occasionally, it'd be nice to see an admission tacked on to the end "...but pigeons make a stormingly good living in them, urban foxes are reaching pest proportions, and rats have never had it so good."

I've got a documentary about Australia on DVD. It had an episode of human influences there. It showed all the bad stuff, like the introduction of cats, dogs and foxes that's decimated the indigenous small marsupial populations. But it also, very refreshingly, showed kangaroos living the good life around the man-made oases that new wells created; the immense flocks of birds that were living off the farmed grain that had been obligingly brought to one location for their convenience; and so on.

When do you ever hear something like "We've massively increased the amount of Carbon dioxide in the air and temperatures are going up too fast! But hey, the warmer it is and the more Carbon dioxide that's available, the faster plants can grow!" Nothing is ever black-and-white: Human changes to the environment are not unreservedly bad for everything. Admit it, it'll make you more credible.

Eightly, and lastly: For God's sake, stop with the "There is overwhelming consensus amongst scientists" thing.

The popularity of a belief is important to politicians and religions. It is irrelevant to science. Science is about fact, not belief. Even if the whole world believes something to be true: if the facts show that it is not true, its popularity is irrelevant. That's the whole point.

Of more relevance is the track record of scientific consensus: There has been widespread consensus that the earth was flat, that it was the center of the universe, that it was created by a god, that illness was not caused by bacteria, that continental drift could not occur. . .

Virtually everything that is currently held as being established truth was at one time at odds with the scientific consensus. Ever read about the reaction to Darwin's theories on evolution? Pasteur's theories on micro-organisms? The word "vaccination" was derived from the first vaccine: Infecting somebody with cowpox stopped them getting smallpox. And yet vaccination was almost universally ridiculed at its inception by people who couldn't see how you could keep people healthy by pumping germs into them.

Going purely by the statistics, you could actually make a very good case that any issue that is widely agreed with by the majority of contemporary scientists is almost certain to be wrong. It always has been so far.

Widespread consensus is something politicians worry about. It has no place in science. In fact, it's almost an embarrassment. Stop treating it as a killer argument, FFS!

That's my rant over with. Thank you for listening.