The Missing Fingerprints of Global Warming: Part 3

In previous posts I checked three of Dr Karl Braganza’s “fingerprints” of climate change he listed in an article in The Conversation on 14/06/2011(my bold):

These fingerprints show the entire climate system has changed in ways that are consistent with increasing greenhouse gases and an enhanced greenhouse effect. They also show that recent, long term changes are inconsistent with a range of natural causes…..

…Patterns of temperature change that are uniquely associated with the enhanced greenhouse effect, and which have been observed in the real world include:

  • greater warming in polar regions than tropical regions
  • greater warming over the continents than the oceans
  • greater warming of night time temperatures than daytime temperatures
  • greater warming in winter compared with summer
  • a pattern of cooling in the high atmosphere (stratosphere) with simultaneous warming in the lower atmosphere (tropopause).

I will look at the 2nd point above, that is, greater continental than oceanic warming.

Time for another reality check.

This is possibly the silliest of Dr Braganza’s claims.  It does not need very great understanding of physics, meteorology, or geography, to see that continents will warm faster than oceans as a result of ANY cause- greenhouse or otherwise- and on any timeframe.

Let’s consider two temperature stations maintained by the Bureau of Meteorology (BOM)- Willis Island 200283, in the middle of the Coral Sea, and Alice Springs 015590, in the middle of Australia.

First, let’s look at a 72 hour timeframe.  Compare these two graphs:

alice daily

 

willis daily

Now here are graphs of monthly mean maxima:alice max

willis max

And minima:alice min

willis min

Finally, these graphs plot anomalies- Maxima:alice v willis max

And minima:alice v willis min

(The trends are not important except to show that they vary more at Alice Springs, and the year-to-year range is greater.)

On all timescales, whether warming is caused by daily, seasonal, or inter-annual factors, Alice Springs warms (and cools) much more rapidly than Willis Island.  Perhaps the specific heat of water compared with land has something to do with it?

Now let’s look at the global picture.  These graphs use data from the University of Alabama (Huntsville) satellite record (UAH) to show the December 1978-May 2013 comparison for Land and Ocean from 85N to 85S.

Global:Land Ocean global

Northern Hemisphere:Land Ocean NH

Southern Hemisphere:Land Ocean SH

Practically identical trend lines for Land and Ocean!

Tropics:Land Ocean tropics

Southern Extra-Tropics:Land Ocean extra-T

Finally, Southern Polar (60-85S)Land Ocean SH polar

Once again it is obvious that “Global” Warming is predominantly a Northern Hemisphere phenomenon.  The Southern Hemisphere refuses to follow Dr Braganza’s claim.

Further, the greater the proportion of land to ocean (Northern Hemisphere), the more land warms relative to the oceans.

Far from being a pattern of temperature change uniquely associated with the enhanced greenhouse effect, this illustrates the higher thermal response of land compared with water.  The only band where the temperature range of the ocean is close to that of the land is the Tropics, which is mostly ocean, and which is the driver of world climate.

Conclusion:

Dr Karl Braganza again has made an assertion that is demonstrably false.  He has failed to explain that any warming will be greater on land than on water and this is not a unique indicator of greenhouse warming.  He should have said that recent, long term changes are consistent with a range of natural causes

FOUR of his fingerprints of climate change are missing.

6 Responses to “The Missing Fingerprints of Global Warming: Part 3”

  1. barry Says:

    I disagree with some of Dr Braganza’s fingerprint statments. One is flat out wrong, and the others lack appropriate caveats.

    Long-term cooling of the stratosphere while the troposphere warms is a correct finger print – if the analysis is global and, of course, long-term. Regional and even hemispheric, or short-term data can buck this expectation, but for the full global satellite record, this is what we are seeing. At least we know the sun is not resposible for warming over the last 34 years (and also because the solar trend is down, or flat for that period, depending which data set is used)

    Days should warm slower than nights – but this is not the case on regional and for short-term analyses, particularly the last 30 years or so. Globally, and over the last century or last 50 years, this appears to be the case. I have read that eventually the diurnal range should not be negative, as days begin to warm as fast as nights, but I do not think that this was anticipated for the last 30 years or so, so it remains a problem with expectations for that period.

    Winters should warm faster than summers – again, this is the case for the long-term global data, but less evident if data is shortened, or regional/S hemisphere is picked out.

    The southern hemisphere is dominated by oceans, so the warming trend is less evident, owing to the great heat capacity of the oceans. Warming is more apparent over land, of which there is a much greater ratio in the N hemisphere. The ration is less clear in the Sothern Hemisphere.

    Ken, what is the temperature trend for Southern Hemisphere landmasses if you exclude Antarctica? (reason for my query below)

    Greater warming over land is definitely not a signature feature of greenhouse warming as you say, Ken. It would be a product of warming for any source, and not uniquely a feature of greenhouse warming.

    We would expect greater warming – over the very long term – over the polar regions than tropical, but the Antarctic is relatively thermally isolated from the rest of the planet (owing to circumpolar winds and ocean currents), so warming may not happen as quickly there. The N pole is surrounded by land, not thermally isolated, and it is evidently warming faster than the tropics.

    There are fingerprints that Dr Braganza has not mentioned. We should be able to see occlusion of infrared radiation in the absorption bands associated with CO2. We should also see an increase in downwelling infrared. The tropopause should rise. The thermosphere should contract.

  2. kenskingdom Says:

    I don’t think there is data available for SH excluding Antarctica.
    There is no sign at all over the satellite record of Antarctica warming, in fact it’s cooling. We don’t have data for the ‘very long term’ for the Antarctic so that can’t be tested. I am not very interested in conjecture (“should”, “expect”).
    One would “expect” that the effects of greenhouse warming would be evident in data for a continent the size of Australia, but greater winter warming and DTR decrease are absent.
    And I am more and more convinced that a global average even of satellite data is meaningless.
    Ken

  3. barry Says:

    There is a portal where you can obtain UAH data with area co-ordinates. Have to try and remember what it was.

    ‘Should’ / ‘expect’ refers to what fingerprints are anticpated to appear under greenhouse warming. Hypothesising like this is a fundamentally useful part of science – prediction and analysis.

    In order to test predictions of “global” warming, data for a city or a small region are near useless. No one place or region is expected (predicted) to represent the globe. Some places will cool and others warm, even under a general warming scenario. Selecting at smaller resolution risks biased results.

  4. kenskingdom Says:

    KNMI might be the portal. Para 2: Totally agree. That’s my interest- using observations to check the predictions. I’m not going to be able to check the data in 100 years time so I’ll stick with the data available now. And greenhouse gases have been increasing for a long enough time that the data ‘should’ be showing up. Re your 3rd para: Australia is a bit bigger than a small region, much bigger than the Antarctic peninsula, Greenland, nearly as big as the Arctic Ocean, about the same as Europe. These regions are very frequently referred to as showing evidence of AGW. And Australia is supposedly the most at risk from climate change. So I’m happy to concentrate on Australia.
    Ken

  5. barry Says:

    Ok, but I think you’ll need longer-term records if you want to focus on Australia. Do you run significance tests on the data?

    The places you mentioned have indeed been referred to as showing evidence of global warming impacts, but I don’t think climate researchers are proposing that they are, individually, proxies for global effects. A serious consideration should note uncertainties with short-term and/or regional trends. Different types of data (eg min/max) have different variance. A sound argument would be based on trends with significance testing and estimated uncertainty.

    Ah yes, KNMI is the portal.

  6. barry Says:

    From the other thread,

    “I calculated climatology for Acorn 1981-2010 instead of 1961-1990, and applied it to the whole period of the satellite record. Apples with apples. I didn’t cherry pick start or finish dates- exactly the same period.”

    I think I understand what you did now. You rebaselined ACORN so that the anomalies would be referenced to 1981 – 2010. I didn’t think you had cherry-picked at all.

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