Climate change

[d000hg]

Drought in the south of England has very little to do with rainfall, but a lot to do with the population doubling under New Labour.

But those immigrants don't wash, right, so they shouldn't be using much

[pjclarke]

Record March temperatures, rivers drying up in the east and fish transferred to other rivers. Widespread hosepipe bans predicted. Any experts on here wish to comment?

I am no expert, however I think that increased abstraction and population density in the SE are the main causes of the hosepipe ban. And it would be wrong to extrapolate from a few records set in a few days at one spot on the globe to climate change, any more than the week long freeze in December 2010 falsified the notion. The World Meteorological Org defines climate as weather aggregated over a thirty year period.

Having said that, more extremes of heat and cold, drought and flood are predicted consequences of a system gaining energy due to more GHGs - the radiative forcing of the CO2 we have already emitted in the last century is equivalent to exploding a million Hiroshima bombs in the atmosphere every day, btw.

There have been a couple of good journal articles on the topic of extreme events and heat waves recently, if you're genuinely interested:

RealClimate: Extremely hot

Nature: Strong Evidence Manmade 'Unprecedented Heat And Rainfall Extremes Are Here ... Causing Intense Human Suffering' | ThinkProgress

The answer to the oft-asked question of whether an event is caused by climate change is that it is the wrong question. All weather events are affected by climate change because the environment in which they occur is warmer and moister than it used to be.

Framing the way to relate climate extremes to climate change

[oscarose]

I am no expert, however I think that increased abstraction and population density in the SE are the main causes of the hosepipe ban. And it would be wrong to extrapolate from a few records set in a few days at one spot on the globe to climate change, any more than the week long freeze in December 2010 falsified the notion. The World Meteorological Org defines climate as weather aggregated over a thirty year period.

Having said that, more extremes of heat and cold, drought and flood are predicted consequences of a system gaining energy due to more GHGs - the radiative forcing of the CO2 we have already emitted in the last century is equivalent to exploding a million Hiroshima bombs in the atmosphere every day, btw.

There have been a couple of good journal articles on the topic of extreme events and heat waves recently, if you're genuinely interested:

RealClimate: Extremely hot

Nature: Strong Evidence Manmade 'Unprecedented Heat And Rainfall Extremes Are Here ... Causing Intense Human Suffering' | ThinkProgress


Framing the way to relate climate extremes to climate change

Thanks for the links. Horizon, tonight, is looking into these extremes of weather and should be interesting.

[wurzel]

It has been the same pattern for the last few years.

Unseasonably warm and sunny in March and April. Then in summer, the jet stream settles just south of the UK & we get one weather front after the other being blown in as a result.

I agree with SB. I miss my summers.

[BlasterBates]

This is interestiing looks like there was global warming in medieval times:

Global warming: Earth heated up in medieval times without human CO2 emissions | Mail Online

Maybe the recent warming is also natural.

[Gonzo]

This is interestiing looks like there was global warming in medieval times:

Global warming: Earth heated up in medieval times without human CO2 emissions | Mail Online

Maybe the recent warming is also natural.

Interesting article but there is a bit of a clue at the end.

The research was recently published online in the journal Earth And Planetary Science Letters and will appear in print on April 1.

[pjclarke]

The usual tabloid science. Hint: if your case relies on the Daily Mail then you're already in a deep hole. The study author has disavowed the Mail's reporting ..

The reporter of that Daily Mail article published it anyway, after we told him the angle that he chose misrepresents our work

Looks like the Mail has unilateraly 'redefined' the MWP as '500 to 1,000 years ago', when in Europe it is more usually taken as the period from around 950 to 1250. 500 years ago we were actually headed into the Little Ice Age, and the existence of a MWP in Antarctica is taken to mean it was global, when in fact there is strong evidence that the Pacific regions was unusually cool at this time. The proxy used does not seem to have the necessary resolution either......

So it goes.

[Churchill]

I am no expert

That's the only post that matters.

[BlasterBates]

More in depth review

http://wattsupwiththat.com/2012/03/2...od-was-global/

Also seems there was a medieval warm period in China as well.

http://www.springerlink.com/content/gh98230822m7g01l/

[pjclarke]

And so we are burning fossil fuels, releasing gigatonnes of carbon from reservoirs where it has remained for millenia into the atmosphere, we do this because the energy density of this stuff is amazing, pretty much the cheapest source of energy we know about, the main driver behind modern economic growth. Fair enough, but it turns out to be a Faustian bargain: the emissions alter the composition of our atmosphere so that it impedes outward radiation, producing a radiative imbalance. Our best estimates are that doubling of CO2 will result in an increase of the planetary average temperature of around 3C, and the consequences are bad news for pretty much everyone, with poorer nations, who have contributed least to the problem, ironically disproportionately affected.

None of this is particularly contoversial, and the rational response would be to scale down our addiction to fossil energy in favour of 'cleaner' alternatives. Of course we will not do this, due to short sighted and near term economic imperatives and widespread scientific ignorance and apathy - no shortage of either round here. Meh.

But what are we to make of the deniers? There was a period about 1,000 years ago, 'the Medieval Warm Period' when temperatures in Europe rose, probably due to a rise in solar output and a quiet period for explosive volcanic eruptions. The argument goes that this MWP shows that because the planet can warm 'naturally', recent warming cannot be manmade. The logic is flawed, and evidence that this period matches recent decades of rapid warming just about everywhere is non-existent. Still the deniers, lacking anything resembing a cogent argument, sieze on the smallest crumb, and conflate it into something it is not.

Blaster points us to an 'in depth' analysis of this study from Blog Scientist Anthony Watts, entitled 'More evidence the Medieval Warm Period was global'.

Let us see what the scientist who did the work and wrote the paper says, shall we?

“It is unfortunate that my research, “An ikaite record of late Holocene climate at the Antarctic Peninsula,” recently published in Earth and Planetary Science Letters, has been misrepresented by a number of media outlets.

Several of these media articles assert that our study claims the entire Earth heated up during medieval times without human CO2
emissions. We clearly state in our paper that we studied one site at the Antarctic Peninsula. The results should not be extrapolated to make assumptions about climate conditions across the entire globe. Other statements, such as the study “throws doubt on orthodoxies around global warming,” completely misrepresent our conclusions. Our study does not question the well-established anthropogenic warming trend.”

It always ends this way. What are we to make of Watts, the Mail and the deniers who quote them?