Friday, April 29, 2016

Tree on Log

In British Columbia. I read that the larger tree is a "nurse log."

Photo: Shayne Kaye/Flickr/Public Domain
Via Slate.

Dangerous Wet Bulb Temperatures in India

It's not even May yet, but at least one city in India has reached dangerous wet bulb temperatures.

A WBT of 30-35°C is dangerous. If you're engaged in physical activity, 27°C or above can be dangerous. 33°C is dangerous even for if you're naked and lying in the shade. Wikipedia says 35°C. At that temperature you literally cannot cool off (without A/C) -- perspiration can't evaporate fast enough; you start to be cooked. Not good if you're poor or don't have electricity (300 M people do not), or you can't afford an A/C.
A sustained wet-bulb temperature exceeding 35 °C (95 °F) is likely to be fatal even to fit and healthy people, unclothed in the shade next to a fan; at this temperature our bodies switch from shedding heat to the environment, to gaining heat from it.[7] Thus 35 °C is the threshold beyond which the body is no longer able to adequately cool itself.
Given the temperature, humidity and surface pressure, this NOAA site returns the WBT. I wrote about WBTs for last year's heat wave in the Persian Gulf here.

I used recent data from Wunderground for Titlagarh, India, in southeastern India, which I read was having a heat wave. (People cannot go out in the street during the day; social events have to take place in the evenings. 99 deaths so far.) On April 24th, their high temperature was 119°F (48.3°C), and their wet bulb temperature reached about 32.4°C. On April 26th it was 113 F° (45.0°C) but more humid, with a WBT of 32.8°C.

And it's only April.

N.b. You really need to know temperature, relative humidity and surface pressure as functions of time; the weather site only gives daily highs, daily lows, and daily aveages. In the above I used the high relative humidities for the day, and the high surface pressure.

With the high temperaure and average RH and average pressure, the numbers are 29,2°C and 31.4°C respectively -- still dangerous.

Thursday, April 28, 2016

What is the Trend in the Airborne Fraction of CO2?

In the wake of the recent CO2 fertilization/greening world paper (I think this is good coverage of what it means, which is not "hallelujah"), And Then There's Physics wrote a post about the airborne fraction (AF) of CO2 -- what fraction of the CO2 we emit stays in the atmosphere? Because as we continue to emit CO2, its AF is by no means guaranteed to stay what it is now, and no one seems to really know how it will change. The concern, of course, is that it increases as nature becomes closer to saturation (the Amazon is already taking up less CO2) and as the ocean continues to warm.

ATTP gave a result by Pierre Friedlingstein that gives a result based on RCP, since 1990:

You can read his discussion.

There are surely studies around that discuss this. But I thought I might have enough spreadsheets laying around to perhaps estimate down-and-dirty the actual trend in airborne fraction.

Here are my data:
  • the atmospheric CO2 fraction since 1959 (the Keeling Curve), where for each year I took the average of 12 months from the monthly Mauna Lea data, from which one can compute the mass of CO2 in the atmosphere, 1959-2015.
  • World CO2 emissions from combustion, cement production and gas flaring from CDIAC, 1751-2005.
  • World CO2 emissions from land use changes from CDIAC, 1850-2005.
  • I assumed atmospheric CO2 for 1850 was 280 ppm.
Here are the trends I find (click to enlarge):

There's considerable annual variation (blue points), but basically the 10-year moving average for AF is flat. So is the total AF since 1850. The last 10 years look like the annual AF has less variation, but that's also where my input data is the less certain (see note below).

N.b. Someone doing this right would need good data all the way to 2015, or up to the last year that is available. One problem in my data are the last two datasets stop in 2005. As an attempt to extend them, I used these data for combustion+cement+flaring for 2006-2008. Beyond 2008 I used IEA data for fossil fuel emissions; for land use emissions I assumed 400 Mt C/yr from 2006-2015, slightly bigger than the last few numbers here up to 2005 (Chinese growth), and flaring emissions of 1.3 Mt C/yr, the value for 2008 (it's a small amount anyway). And I assumed land use emissions per year for 2007-2015 were the average of the previous 10 years, which is 1,479 Mt C/yr. I ignored methane emissions, which converts to CO2 after several years. (I said, down-and-dirty.) 

Wednesday, April 27, 2016

A Batch of Interesting Papers

There are a bunch of especially interesting papers in tonight's table of contents from Geophysical Research Letters. I haven't read any of them yet, but am posting them because (1) some pertain to things being discussed back on this post, (2) you can read yourself if so motivated.

I'll post the paper's citation, a link to it, and the three-bullet summary of the paper from the table of contents:

"Predictability of the recent slowdown and subsequent recovery of large-scale surface warming using statistical methods," Michael E. Mann et al, GRL (8 April 2016).

"Emergence of heat extremes attributable to anthropogenic influences," Andrew D. King et al, GRL (2 April 2016).

"Nonlinearities in patterns of long-term ocean warming," Maria A. A. Rugenstein et al, GRL (4 April 2016).

"The impact of groundwater depletion on spatial variations in sea level change during the past century," Emeline Veit et al, GRL (2 April 2016).

"Ice mass loss in Greenland, the Gulf of Alaska, and the Canadian Archipelago: Seasonal cycles and decadal trends," Christopher Harig et al, GRL (5 April 2016).

Tuesday, April 26, 2016

Sloooooooooow Progress on Renewables

I assembled this for something I'm working on:

Here renewable energy = hydro + geothermal + solar/PV + wind + biomass

Although renewables have increased by about 4 percentage points in 8 years, which is -0.5 pct pts/year. Not fast enough. Drew Shindell says we need a decrease in fossil fuel emissions of something like 2.7%/yr.

I also came up with this:

Data from EIA.

Monday, April 25, 2016

Is Abdussamatov's Prediction of a TSI Collapse Coming True?

Remember that dip in total solar irradiance (TSI) that had some people excited last week?

It's gone. It was just a sunpot:

However, TSI is doing something interesting: it's dropping relatively fast now, down about 1 W/m2 since its peak in early 2015.

LASP's daily record only starts in early 2003. PMOD starts in 1978, and, except for the lower solar maximum for this latest cycle, it doesn't appear anything particularly unusual is going on:

It will be interesting to see the current cycle's minimum, but that won't be for another 5-6 years. Will it match this Internet-famous prediction from Abdussamatov in his paper that finally seems to have gotten published in a journal titled Thermal Science:

Is his prediction coming true?

Here's a plot showing about where he says TSI should be in 2016:

Abdussamatov says TSI should now be about 0.7 W/m2 below the baseline of the cycles from 1980-2010. The PMOD data certainly doesn't show that -- it's still above that baseline, by about 0.3 W/m2. Abdussamatov is too low by a whole W/m2, which is a significant amount when you're talking about the sun.

So I would say that, so far, Abdussamatov's prediction is failing, and there's no indication of the TSI collapse he predicted. We have not entered the his Little Ice Age.

Thursday, April 21, 2016

The Shock of Seeing Anomalies Above 2°C

This month's data -- temperatures, global, land and sea; lower troposphere up to lower stratosphere, sea ice extent and volume, Mauna Loa CO2 and all the ocean indices -- are now out, except for HadCRUT4 and, then, Cowtan & Way. They're always about two weeks later than GISS and NOAA.

To me, the most astonishing numbers are from NOAA's measurement of the average global land temperature, averaged across the globe's surface. The last two months have been well above 2°C:

I've been paying close attention to all these monthly data for many years now, and seeing anomalies -- any anomaly -- approaching +2.5°C is really shocking, in quite an other worldly kind of way. (The anomaly is with respect to the 1901-2000 average*.)

NOAA's global land anomaly for March 1998 is only +0.88°C. This March it is +2.33°C.

That's a lot of warming in 18 years, from one big El Nino to the next one.

I don't know if the 2°C diplomatic target means 2°C for the change in the global surface average, or for a change anywhere -- and since the number is, as far as I know, just a guess at a target that is both doable and not too dangerous, I doubt anyone even thought to think that question much....

Americans: an anomaly of 2.33°C = 4.2°F. That is perceptable without instruments.

The warming has been coming at a steady 0.15-0.2°C/decade since 1990. So when I see stories saying that 93% of the Great Barrier Reef has died because of exceptionally warm ocean water, I start to feel angry about that. Deeply angry -- at everyone who is denying serious anthropogenic climate change and who is working hard to prevent us from saving the world that we know and love. And angry at those I personally know who are denying it.

And I don't just mean angry in a scientific way. The Great Barrier Reef was one of the marvels of the Universe. If you don't care about marvels of the Universe, then what in the hell do you care about?

* And can I say, is it really too much to ask that all the different research groups use the same baseline? Yes, I know that converting between them is doable and mathematically trivial. But's it's also tedious. And, yes, I know that trends are independent of baselines. But still....