The Latif Controversy:”IPCC scientist: Global cooling headed our way for the next 30 years?”

Mojib Latif is considered to be one of the world’s top climate modelers and a prominent contributor to IPCC reports…

Latif, is a professor at the Leibniz Institute at Germany’s Kiel University and an author of the U.N.’s Intergovernmental Panel on Climate Change (IPCC) report. Latif is a prominent scientist in the UN’s IPCC climate research group.Latif thinks the cold snap Americans, Brits, and Europeans have been suffering through is the beginning of another cycle, this one a down cycle. He says we’re in for 30 years of cooler temperatures.

Watts Up With That?

Apparently, at least some of the scientists associated with the IPCC are no longer able to “hide the decline.”

From NASA Earth Observatory: December temperatures compared to average December temps recorded between 2000 and 2008. Blue indicates colder than average land surface temperatures, while red indicates warmer temperatures.

According to the left-wing blogosphere (Media Matters, Climate Progress, etc.) Dr. Latif says that he is being misquoted, misinterpreted and otherwise misunderstood.   If Dr. Latif was “misrepresented,” it’s due to the fact that over the last two years, he has written and/or said on numerous occasions that the climate will cool for the next 1-3 decades and that at least half of the warming of the 20th century was due to natural climate cycles.

From Nature, May 1, 2008…

Nature 453, 84-88 (1 May 2008) | doi:10.1038/nature06921; Received 25 June 2007; Accepted 14 March 2008; Corrected 8 May 2008

Advancing decadal-scale climate prediction in the North Atlantic sector

 N. S. Keenlyside1, M. Latif1, J. Jungclaus2, L. Kornblueh2 & E. Roeckner2[…]The climate of the North Atlantic region exhibits fluctuations on decadal timescales that have large societal consequences…

[…]

Thus these results point towards the possibility of routine decadal climate predictions. Using this method, and by considering both internal natural climate variations and projected future anthropogenic forcing, we make the following forecast: over the next decade, the current Atlantic meridional overturning circulation will weaken to its long-term mean; moreover, North Atlantic SST and European and North American surface temperatures will cool slightly, whereas tropical Pacific SST will remain almost unchanged. Our results suggest that global surface temperature may not increase over the next decade, as natural climate variations in the North Atlantic and tropical Pacific temporarily offset the projected anthropogenic warming.

LINK

From New Scientist, September 9, 2009…

FORECASTS of climate change are about to go seriously out of kilter. We could be about to enter one or even two decades of cooler temperatures, according to one of the world’s top climate modellers.”People will say this is global warming disappearing,” Mojib Latif told more than 1500 climate scientists gathered at the UN’s World Climate Conference in Geneva, Switzerland, last week. “I am not one of the sceptics. However, we have to ask the nasty questions ourselves or other people will do it.”[…]Latif predicts that in the next few years a natural cooling trend will dominate the warming caused by humans. The cooling would be down to cyclical changes in the atmosphere and ocean currents in the North Atlantic, known as the North Atlantic Oscillation (NAO) and the Atlantic Meridional Oscillation (AMO).Breaking with climate-change orthodoxy, Latif said the NAO was probably responsible for some of the strong warming seen around the globe in the past three decades. “But how much? The jury is still out,” he told the conference. The NAO is now moving into a phase that will cool the planet.[…]

LINK

From The Guardian, January 11, 2010…

Latif said his research suggested that up to half the warming seen over the 20th century was down to this natural ocean effect…

LINK

From The Telegraph, January 11, 2010…

The world could be in for a spell of cooler temperatures, rather than hotter conditions, as a result of cyclical changes in ocean currents for the next 20 or 30 years, it is predicted.Research by Professor Mojib Latif, one of the world’s leading climate modellers, questions the widely held view that global temperatures will rise rapidly over the coming years.[…]He told a UN conference in September that changes in ocean currents known as North Atlantic Oscillation could dominate over man-made global warming for the next few decades.Controversially, he also said that the fluctuations could also be responsible for much of the rise in global temperatures seen over the past 30 years.[…]

LINK

Dr. Latif has repeatedly said that the shift of the NAO from positive to negative will lead to 10 to 30 years of global cooling and that as much as half of the late 20th century warming was due to natural climate oscillations. He has only become misquoted, misinterpreted or otherwise misunderstood since the story was picked up by Fox News and Watts Up With That?.

You can view Dr. Latif’s presentation to the September 2009 World Climate Conference here: LINK.

This is slide #3 from his presentation…

Latif, 2009 World Climate Conference, Slide #3

Here is a zoomed-in view of three decades of cooling…

Latif's "Three decades of cooling."

Latif is predicting that after the NAO switches back to warm mode (~2030) global warming will resume… Which it will; although it won’t warm anywhere near as much as Latif predicts.. The unanswered questions are, “How much will it cool over the next 25 years? And how much will it warm during the next ~30-yr warming leg?”

The key point is that just a few years ago, people like Latif were not taking these decadal and multi-decadal natural climate oscillations into account when making their model projections. This is one of the reasons that the climate models always forecast more warming than actually occurs. The lack of warming since 1998 has forced modelers like Latif to incorporate the cycles into the models.

This is drastically different from the IPCC’s most recent assessment report. IPCC AR4 Summary for Policy Makers (2007) stated that…

“Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.”

And that…

“For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios. Even if the concentrations of all greenhouse gases and aerosols had been kept constant at year 2000 levels, a further warming of 0.1°C per decade would be expected.”

The IPCC defines “very likely” as having a greater than 90% probability.

-In 2007 most of the late 20th century warming was due to anthropogenic greenhouse gases.
-In 2009 less than half of the 20th century warming was due to anthropogenic greenhouse gases according to Dr. Latif.

-In 2007 a warming of 0.2°C per decade over the next twenty years was projected for a range of emissions scenarios and 0.1°C per decade of warming was projected for the ideal emissions scenario.
-In 2009 a cooling trend was projected over the next twenty years by Dr. Latif, irrespective of emissions scenarios.

Here’s the “kicker”…

If I assume that all of the warming trend since 1850 was due to CO2, an equation can be derived to relate CO2 to the low-frequency component of temperature change and I can project a maximum possible warming from CO2 over the next 100 years. Assuming a steady increase of 1.95 ppmv CO2 per year (the average over the last decade) over the next 100 years, I get a maximum possible warming of 0.1°C per decade…

Maximum possible CO2-driven warming over next century at a constant increases of 1.95 ppmv CO2 per year.

It’s mathematically impossible for a 1.95 ppmv/yr growth of atmospheric CO2 to cause more than 1.0°C of warming over the next 100 years. Since we know that CO2 caused far less than half of the warming since 1850, the maximum warming over the next century will be a lot less than 1.0°C.  It will actually be immeasurably small.

But… For the sake of argument… Let’s compare the maximum 100% CO2-driven temperature change to Dr. Latif’s new projection which supposedly accounts for natural climate oscillations…

Latif model vs. maximum possible CO2 warming.

Latif is projecting three times as much warming over the next century than is mathematically possible for a world in which all of the warming since 1850 was CO2-driven.

Latif must be employing on or more of the following to derive so much warming:

  1. An exponential annual increase of atmospheric CO2… A wild guess.
  2. A higher climate sensitivity to CO2… Provably false.
  3. Positive feedback loops… For which there is no evidence of ever having previously occurred.

I will be running a series of models to see just how much CO2 would have to be added to the atmosphere to achieve Latif’s degree of warming… So… Stay tuned!

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