Wednesday, December 16, 2015

Don Wuebbles: Dangerous Climate Change is Already Here


David in Cal said...

I'm a retired reinsurance company chief actuary, so I know a lot about this topic. A few points:

1. It's conceivale that future climate change might impact extreme weather events. My comments relate only to the impact of climate change so far.

2. Munich Re has long been in the alarmist camp. It's in their interest. It justifies them charging higher prices.

3. The IPCC has pretty much said that there's no evidence that climate change has increased extreme events so far, except for heat spells.

4. The cost of an event is often reported as the insured loss. As Wuebbles says, the trend is affected by population, wealth and inflation. It's also affected by increasing amounts of insurance purchased, increase in structures that could be damaged, and increase in structures in exposed areas. This last point is important. During recent decades, many hotels and other buildings have been erected near the coast.

5. That Munich Re chart looks impressive, but one needs to know how they defined an "event". If their definition is tied to monetary loss, then the chart is not an indication of increasing events. Rather, it might be showing the increase in the cost of a given event due to the factors mentioned in #4.

6. Looking at types of events that have grown in a period of a couple of decades is pretty much meaningless. Weather has lots of randomness. And, there are lows as well as highs. which Wuebbles ignored. E.g., consider hurricanes. Hurricanes are classified as "major" or "minor" based on the Saffir-Simpson scale. Right now we're in the longest period in recorded history where no "major" hurricane has made US landfall. But, it would be wrong to conclude that climate change has caused a reduction in large hurricanes. There's just too much randomness to draw any conclusion from this 10-year lull.

7. BTW the absense of "maor" hurricanes hitting the US along with high reinsurance rates have led to huge profits for Munich Re and other reinsurance companies.


David Appell said...

If Munich Re charged higher or unreasonable prices, customers would go elsewhere in the free market.

David in Cal said...

David, all us reinsurers charged higher prices. In 2005 a bunch of large hurricanes hit the US, especially Katrina. Meanwhile, alarmists were saying that global warming had increased the frequency of large hurricanes. By then pricing was done using a few models, such as CatMap, EQE, RMS, etc. All these models made big judgmental increases in the assumed hurricane frequency and severity. Their reinsurer clients were only too happy to see those increases. The market price for US windstorm jumped a lot.

Nobody really knows whether the prices are "reasonable". Huge hurricanes are rare, yet they represent a big part of the reinsurer's cost. There also appears to be a 20 or 30 year cycle in hurricanes. Therefore, there's a lot of uncertainty in the pricing.


David Appell said...


Increase in number of North Atlantic hurricanes and storms:

David Appell said...

David in Cal:
Re your #3:

Yet again you have mischaracterized the science.

See the IPCC SREX SPM pp 5-7, which is about more than heat spells:

David Appell said...

David: And even if it WERE just heat spells, why is that acceptable?

I'm compiling loss of human life due to climate change. For heat waves, I already have

2003 70,000 European heat wave
2010 17,905,000 northern hemisphere heat wave
2010 9,516 Moscow heat wave
2015 2000 Pakistan heat wave
2015 2500 India heat wave

David in Cal said...

Far more people die of cold than of heat. E.g., in the UK alone, the expected number of deaths due to cold this winter is projected to top 40,000.


David Appell said...

David, so we should heat up the entire world just because Britian is too cheap to provide its poor elderly with heat?

That'd be like cooling down your entire house just so the butter doesn't melt if it's left out of the fridge.

In other words, it'd be really dumb. Do you think people in the tropics want it even hotter there?

David Appell said...

The article you cited even says as much:

“Winter deaths are a tragedy for families of those affected but it appears the underlying causes of these deaths have still not been properly addressed."

People in Maine aren't massively dying from the cold. Nor in Canada, or Russia, or the Scandanavian countries.

You haven't throught this through.

David in Cal said...

David -- here's my belief, for what it's worth. You may not agree. Global warming is a serious problem. CO2 emissions are warming the planet at some unknown rate. I think the rate of warming is probably around 1 - 1.5 deg C per century, but it might be considerably faster for all I know. Whatever the rate of warming is, sooner or later the warming will be harmfulo. We will have to deal with it.

However... due to a variety of reasons, there are a lot of ridiculous statements and terrible science being done. In particular, claims that global warming has already done harm. The world just hasn't warmed that much since CO2 emissions became significant 50 years ago, or so. The kind of changes that massive global warming might cause can't be seen on so short a time scale. People who claim to be able to already discern some baleful impact of global warming are mostly talking through their hats. IMHO their dubious research subtracts from the seriousness of the long-term problem.


David Appell said...

David: Essentially ALL of modern warming has come since 1950: 0.9 C.

That's the global average. It's been more on land (1.2 C).

When the dinosaurs lived the globe was only 6 C warmer. At the depth of the last ice age it was only 8 C cooler.

So it doesn't take much warming or cooling to have a huge effect on the planet. So it's no surprise climate change is already affecting people today. The California drought isn't affecting people? Floods in third world countries, like the more than 5000 deaths in the 2013 flooding in Uttarakhand, India that was linked to climate change? 2000 dead in this year's Pakistan heat wave, and 2500 in India's?

Americans aren't much affected by these changes -- we're right, have great homes, A/C, etc. There are at least 3B people in the world who live very poor, harsh lives.

Do they matter at all?

The climate system has huge inertia. Scientists understand this, but the public doesn't. It takes millennia for these changes to fully play out, and they are just now in the beginning stages. We've made even more change inevitable -- each year we add 0.015-0.02 deg C to the expected peak warming -- 0.15 to 0.20 C every decade. And that's if we're lucky and warming isn't on the high side of the probability distribution.

How much risk is acceptable?

David Appell said...

> 5000 deaths
flooding in Uttarakhand, India
linked to climate change:

David in Cal said...

"The Stanford University-led research unearthed tenuous links between the tragedy and rising greenhouse gas levels."

"the researchers concluded that the heavy June rainfall was a once-in-a-century-or-so phenomenon."

Did global warming make this once-in-a-century event more likely? IMHO there's no way to tell.

David in Cal said...

Both side claim that poor nations are better off in the next few decades if their program is followed. David Appel above makes the case the poor nations are being hurt right now due to climate change. So, taking remedial steps helps the poor nations. The other side asserts that poor nations are being hurt now if they're discouraged from making greater use of of fossil fuels for electricity, transportation, air-conditioning, etc.

David Appell said...

"The other side asserts that poor nations are being hurt now if they're discouraged from making greater use of of fossil fuels for electricity, transportation, air-conditioning, etc."

I don't know of anyone who is discouraging the poor from using fossil fuels for electricity, transportion, and A/C.

Do you?

The US got rich by burning fossil fuels and dumping the waste into the atmosphere. From a moral standpoint, poor countries have every right to do the same.

Global warming depends on cumulative emissions, not current emissions. The US is by far the leader in cumulative emissions: as of 2012

US: 366 Gt CO2
China: 150 Gt CO2
India: 38 Gt CO2

That's why the US needs to clean up its game first, and provide reparations to developing countries hurt by the US's lack of concern for harming the climate.

David Appell said...

"Did global warming make this once-in-a-century event more likely? IMHO there's no way to tell."

Global warming has increased the water vapor content of the atmosphere.

It increases by about 7% per degree C of warming. (Clausius-Claperyon equation.)

I don't see what's controversial about predicting this will lead to more rain and heavier rainfall events.

David Appell said...

Evidence for an increase in atmospheric water vapor:

"Identification of human-induced changes in atmospheric moisture content," B.D. Santer et al, PNAS (2007) 104, 15248–15253.

"How much more rain will global warming bring?" F.J. Wentz, Science (2007), 317, 233–235.

"Analysis of global water vapour trends from satellite measurements in the visible spectral range," S. Mieruch et al, Atmos Chem Phys (2008), 8, 491–504.

David in Cal said...

OK. By the same token, global warming should mean fewer and/or less severe droughts and more land changing from barren and dry to available for agriculture.

John Kerry, in a speech given in China to the APEC economies, said, "we reaffirmed our commitment to phase out inefficient fossil fuel subsidies. I can’t emphasize enough how critical it is for APEC to lead the way in reducing greenhouse gas emissions." I am not 100% clear, but I think he was talking about fossil fuel subsidies to the APEC countries. See:

David Appell said...

"By the same token, global warming should mean fewer and/or less severe droughts and more land changing from barren and dry to available for agriculture."

Nope, that's not the way the science works out.

There are a lot of rich, high polluting countries in APEC: the US, Canada, Australia, New Zealand, Russia:

They need to cut first - the US most of all. Nothing else is fair. American don't have some special right to their high per-capita emissions that China or India doesn't have.