Timothy Birdnow

Timothy Birdnow

Below is an exchange at CCNet between Climate Alarmist Andrew Glikson and Paul Biggs. Glikson lays out a case that sounds solid if one doesn`t know how weak it truly is. Dr. Biggs does what I lacked the tiime to do since it posted; demolishes it completely.

21ST CENTURY CLIMATE TRENDS

Andrew Glikson [geospec@iinet.net.au]
(Earth and paleo-climate research)

Recent climate developments in the polar cryosphere and the oceans suggest the atmosphere is tracking toward conditions similar to those of ~ 2.8 Ma (mid-Pliocene: + 2 to 3C; sea level + 25±12 metres; permanent El-Nino) (Haywood and Williams, 2005; Dowsett et al., 2005) and a possible tipping point. The polar sea ice and continental ice sheets, which serve as Earth’s climate thermostat, are changing at an accelerated rate. Developments to date include:

A. The rise of mean Arctic and sub-Arctic temperatures in 2005-2008 by near +4C relative to 1951-1980 (NASA-GISS);

B. Arctic Sea ice melt rates of ~ 5.4% per-decade since 1980, increasing to >10% per year during 2006-2007 (NSIDC, 2008);

C. West Antarctica sea ice melt rates >10% per decade culminating in mid-winter ice shelf breakdown (Wilkins ice shelf; June, 2008, NSIDC, 2008);

D. Advanced melt of Greenland ice;

E. Slow-down of the North Atlantic thermohaline conveyor belt and down-welling water columns (NASA, 2004; Bryden et al., 2005), with attendant danger of its cessation analogous to conditions ~8.2 kyr ago (Alley et al., 1997);

F. Temperature projections for the North Atlantic Ocean (Keenlyside et al., 2008) may reflect the effect of Greenland ice melt waters;

G. Increased frequency and intensification of categories 4 and 5 hurricanes (Webster et al., 2005) and, not least, elevated methane release from Arctic Sea sediments and sub-Arctic permafrost (Walter et al., 2006; Rigby, 2008).

Increasingly an analogy emerges between these developments and aspects of abrupt climate changes associated with the last glacial termination. As stated by Alley et al. (2003) Large, abrupt, and widespread climate changes with major impacts have occurred repeatedly in the past, when the Earth system was forced across thresholds. Ice core and sedimentary evidence for the Pleistocene (1.8 Ma 10,000 years-ago) demonstrate abrupt glacial terminations, intra-glacial global warming events (Dansgaard-Oeschger cycles; Broecker, 2000; Ganopolski and Rahmstorf, 2002; Braun et al., 2005) as well as sharp to protracted cooling periods. The latest glacial termination includes a number of tipping points which involve sharp rise and fall of temperatures by several degrees C over time scales of centuries, decades, or even a few years (Clark et al., 2003; Kobashi et al., 2008; Steffensen et al., 2008), affecting both high latitudes and tropical zones (Hughen et al., 1996).

Comparisons between CO2, CH4, temperature and sea level changes during glacial terminations, post-1850 and 20th - 21st century climate change rates (Glikson, 2008) suggest:

CO2 rise rates: Late 20th century and early 21st century rates averaging 1.45 ppm/yr and rising to 1.8 ppm/yr in 2006 and 2.2 ppm/yr in 2007, exceed 1850-1970 rates by factors of ~4–5 and are two orders of magnitude higher than mean CO2 rise rates of the last glacial termination (~0.014 ppm/yr) (Rahmstorf et al., 2006; Global Carbon Project, 2008).

CH4 rise rates: A 10 ppb/yr rise in methane during 2007 (http://web.mit.edu/newsoffice /2008/techtalk53-7.pdf), exceeding the 1850-1970 rise (~5.4 ppb/yr), is orders of magnitude higher than during the last glacial termination. Methane deposits potentially vulnerable to climate change reside in permafrost (~ 900 GtC), high latitude peat lands (~ 400 GtC), tropical peat lands (~ 100 GtC), vulnerable vegetation (~ 650 GtC) and methane hydrates and clathrates in the ocean and ocean floor sediments (>16,000 GtC). The total exceeds the atmospheric level of carbon (~ 750 GtC), carbon emissions to date (~ 305 GtC) and known economic carbon reserves (>>4000 GtC).

Temperature rise rates: Mean temperature rise rates of 0.016C during 1970 - 2007 were about an order of magnitude higher than during 1850-1970 (0.0017C) and the last glacial termination. As indicated by deuterium studies of Greenland ice cores, abrupt tipping points during the last termination (14.7 11.7 kyr) resulted in extreme temperature changes on the scale of several degrees C in a few years (Steffensen et al., 2008).

Sea level rise rates: Mean sea level rise rate of ~0.32 cm/yr during 1988-2007 more than doubled relative to the mean ~0.14 cm/yr rate of 1973-1988 and three times those of 1850-1970. In so far as doubling of sea level rise rates continues at this rate through the 21st century, they may approach rates similar to those of the last glacial termination (1.3 – 1.6 cm/yr) before mid-century, with sea level rise by several metres toward the end of the century as estimated by Hansen et al (2007).

Whereas larger ice sheets existed on Earth at the outset of the last glacial termination, when the large Laurentian and Fennoscandian ice sheets began to melt, than during the Holocene, comparisons between climate forcings during the glacial termination and those operating since about 1750 may be instructive:

1. The last glacial termination, triggered by insolation peaks, involved total radiative forcing rise of about 6.5 Watt/m2, including ~3.0±0.5 Watt/m2 induced by rising greenhouse gases (GHG: CO2, CH4, NxO) and 3.5±1.0 Watt/m2 induced by lowered albedo associated with melting of ice sheets and spread of vegetation. Both factors, including their feedback effects, result in mean global temperature rise of ~ 5.0±1.0C (Hansen et al., 2008).

2. Since about 1750 global warming is driven by radiative GHG forcing of near + 3.0 Watt/m2 consequent on rise of GHG (CO2, CH4, NxO, ozone, halocarbons), compensated in part by albedo increase due to land clearing (- 0.2 Watt/m2), aerosols ( - 0.5 Watt/m2) and clouds (- 0.7 Watt/m2). When the albedo loss due to melting of the Arctic and Antarctic sea ice, the margins of Greenland and Antarctic ice sheets and mountain glaciers, is accounted for, the total forcing would be tracking toward values about half those of the last glacial termination of 6.5±1.5 Watt/m2.

Detailed deuterium proxy-based paleo-temperature studies of Greenland ice cores GISP-2 indicate that, far from smooth, the transitions associated with the glacial terminations involved abrupt tipping points where temperatures rose or fell sharply by several degrees C over time scales as short as a few decades or even a few years (Kobashi et al., 2008; Steffensen et al., 2008). A potential onset of such tipping points in the context of 21st century climate change is consistent with observations pertaining to the last glacial termination, current methane release from sediments off-shore Siberia and from permafrost, Arctic Sea ice melt, Antarctic sea ice and ice shelf melt and intensifying Atlantic hurricanes.

A marked climate tipping point is defined about 1975-76, with abrupt rise of temperature and temperature rise rates. 1975 2008 climate change developments incurred CO2 rise by 55 ppm (332-387 ppm) and mean temperature rise of ~ +0.9C for the Northern Hemisphere (mean CO2 rise ~ 1.7 ppm/yr; temperature rise 0.027C/yr; 0.016C per 1 ppm CO2). In so far as the relations between CO2 and temperature during 1975-2008 can be used as a baseline, a rise of CO2 levels to 450 ppm by 2050 would result in minimum additional temperature rise by approximately 1.0C relative to 2008.

Conservative estimate of the “climate sensitivity”, estimated at 3 degrees rise per doubling of CO2 for fast climate feedback processes (water vapor, clouds, aerosols, sea ice), implies a rise of CO2 by 100 ppm (from 450 to 550 ppm CO2) will elevate global temperatures by about 1.0+/-0.5C, where a trajectory toward 550 ppm threatens to raise temperatures to about 2.6C later in the 21st century. However, slow climate change feedbacks (reduced continental ice sheets, increased vegetation cover in permafrost-melt areas) ensue in climate sensitivity of ~ 6C per doubling of CO2 consistent with the last glacial termination (Hansen et al., 2008).

Given the onset of the Antarctic ice sheet at or below 500 ppm CO2 at ~34 Ma (late Eocene), and of the Arctic Sea ice below 400 ppm at 2.8 Ma (mid-Pliocene) (Haywood and Williams, 2005), the projected consequences of CO2 trajectories toward 550 ppm are likely involve climate tipping points.

End Piece

(From Tim; Now our old friend Paul Biggs demolishes Andrew Glikson`s whole argument):

Paul Biggs [p.m.biggs@bham.ac.uk]

Here is my brief response to yet more tiresome climate alarmism from Andrew Glikson (CCNet 30/11/2008):

1) Arctic/Antarctic:

Why compare current Arctic temperatures with the arbitrary period cherry picked period 1951-1980? Why not compare the Arctic warming around the 1920s-1930s, or 1000 years ago, or even 6000-7000 years ago?

Less ice in the Arctic Ocean 6000-7000 years ago: Recent mapping of a number of raised beach ridges on the north coast of Greenland suggests that the ice cover in the Arctic Ocean was greatly reduced some 6000-7000 years ago. The Arctic Ocean may have been periodically ice free. “The climate in the northern regions has never been milder since the last Ice Age than it was about 6000-7000 years ago. We still don’t know whether the Arctic Ocean was completely ice free, but there was more open water in the area north of Greenland than there is today,” says Astrid Lyså, a geologist and researcher at the Geological Survey of Norway (NGU).
http://www.ngu.no/en-gb/Aktuelt/2008/Less-ice-in-the-Arctic-Ocean-6000-7000-years-ago/

Arctic sea ice has undergone a strong recovery this year following the peak melt, putting the recovery on a par with 2002. Winds and atmospheric circulations have played a significant role in recent sea ice losses. See papers referenced at my website Climate Research News:

New Papers on the Role of Winds and Atmospheric Circulations in Arctic Sea Ice Loss:
http://climateresearchnews.com/2008/11/new-papers-on-the-role-of-winds-and-atmospheric-circulations-in-arctic-sea-ice-loss/

Winds are Dominant Cause of Greenland and West Antarctic Ice Sheet Losses:
http://climateresearchnews.com/2008/10/winds-are-dominant-cause-of-greenland-and-west-antarctic-ice-sheet-losses/

The East and West Antarctic ice sheets have demonstrated divergent climate histories over the past 14 million years, a phenomenon that persists today. Data from the Dry Valleys reveals an East Antarctic Ice Sheet that is high, dry, cold, and stable, at least in its central area. The ANDRILL cores suggest a more volatile West Antarctic Ice Sheet that is subject to the changing temperatures of the sea in which it wades. (ANTARCTICA: Freeze-Dried Findings Support a Tale of Two Ancient Climates. Science 30 May 2008: 1152-1154)

Glaciers in Norway Growing Again
http://www.dailytech.com/Glaciers+in+Norway+Growing+Again/article13540.htm

Bad weather was good for Alaska glaciers http://www.adn.com/news/environment/story/555283.html

2) Slow-down of the North Atlantic thermohaline conveyor belt:

The 2005 Bryden et al paper Glikson refers to was debunked in Science magazine: ‘False Alarm: Atlantic Conveyor Belt Hasn’t Slowed Down, Kerr, Science 17 November 2006: 1064a’

3) Hurricanes:

The attempts to link hurricane frequency or intensity with ‘global warming’ have floundered, e.g.
‘Multi-decadal variability of Atlantic hurricane activity: 1851-2007,’ by Petr Chylek and Glen Lesins, Journal of Geophysical Research-Atmospheres (doi:10.1029/2008JD010036) (2008).

The Abstract states:
An analysis of Atlantic hurricane data (HURDAT), using a hurricane activity index that integrates over hurricane numbers, durations and strengths during the years 1851-2007, suggests a quasi-periodic behavior with a period around 60 years superimposed upon a linearly increasing background. The linearly increasing background is significantly reduced or removed when various corrections were applied for hurricane under-counting in the early portion of the record. The periodic-like behavior is persistent in uncorrected HURDAT data as well as in data corrected for possible missing storms. The record contains two complete cycles: 1860-1920 and 1920-1980. The 2004 and 2005 hurricane seasons were unusual in that two intense hurricane seasons occurred in consecutive years. The probability for this happening in any given year is estimated to be less then 1%. Comparing the last 28 years (1980-2007) with the preceding 28 years (1953-1980) we find a modest increase in the number of minor hurricanes (category 1 and 2), however, we find no increase in the number of major hurricanes (category 3-5). The hurricane activity index is found to be highly correlated with the Atlantic Multi-decadal Mode (AMM).

A document-based 318-year record of tropical cyclones in the Lesser Antilles, 1690-2007 by Michael Chenoweth and Dmitry Divine, GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS, VOL. 9, Q08013, doi:10.1029/2008GC002066, 2008

Abstract:
The most comprehensive and longest document-based time series of tropical cyclone activity for any area of the world is presented for the Atlantic and Caribbean region of the Lesser Antilles for the years 1690-2007. Newspaper accounts, ships’ logbooks, meteorological journals, and other document sources were used to create this new data set, and a new methodology was applied for classifying historical tropical cyclone intensity. This compilation estimates the position and intensity of each tropical cyclone that passes through the 61.5°W meridian from the coast of South America northward through 25.0°N. The additional resources used here fills in gaps in the HURDAT record, which undercounts tropical storms and hurricanes by 28% (7%) in the years 1851-1898 (1899-1930) over populated islands from 12 to 18°N. The numbers of tropical cyclones show no trends that were significant at the 5% level. The time span 1968-1977 was probably the most inactive period since the islands were settled in the 1620s and 1630s.

4)Methane:

2007 Global Atmospheric Methane Rise Not Due to Man:

Boston (MA) - Scientists at MIT have recorded a nearly simultaneous world-wide increase in methane levels. This is the first increase in ten years, and what baffles science is that this data contradicts theories stating man is the primary source of increase for this greenhouse gas. It takes about one full year for gases generated in the highly industrial northern hemisphere to cycle through and reach the southern hemisphere. However, since all worldwide levels rose simultaneously throughout the same year, it is now believed this may be part of a natural cycle in mother nature - and not the direct result of man’s contributions. T G daily: MIT scientists baffled by global warming theory, contradicts scientific data.

Rigby, M., R. Prinn, P. Fraser, P. Simmonds, R. Langenfelds, J. Huang, D. Cunnold, P. Steele, P. Krummel, R. Weiss, S. O’Doherty, P. Salameh, H. Wang, C. Harth, J. Mühle, and L. Porter (2008), Renewed growth of atmospheric methane, Geophys. Res. Lett., doi:10.1029/2008GL036037

Arctic ‘Methane Chimneys’ Alarmism - A Note of Caution http://climateresearchnews.com/2008/09/arctic-methane-chimneys-alarmism-a-note-of-caution/

Scientists claim to have discovered evidence for large releases of methane into the atmosphere from frozen seabed stores off the northern coast of Siberia. But climate experts have expressed caution at the claims, which have yet to be published in a peer reviewed scientific journal. Methane release from stores of so-called gas hydrates, that can form on land or under the sea, is not new to researchers. Huge quantities are known to exist in the Arctic, but special circumstances would need to exist for significant releases to occur.

5) Sea level rise:

Kinematic Constraints on Glacier Contributions to 21st-Century Sea-Level Rise, W. T. Pfeffer, J. T. Harper, S. O’Neel, Science, 5 September 2008: Vol. 321. no. 5894, pp. 1340 - 1343. DOI: 10.1126/science.1159099

Abstract:
On the basis of climate modelling and analogies with past conditions, the potential for multimeter increases in sea level by the end of the 21st century has been proposed. We consider glaciological conditions required for large sea-level rise to occur by 2100 and conclude that increases in excess of 2 meters are physically untenable. We find that a total sea-level rise of about 2 meters by 2100 could occur under physically possible glaciological conditions but only if all variables are quickly accelerated to extremely high limits. More plausible but still accelerated conditions lead to total sea-level rise by 2100 of about 0.8 meter. These roughly constrained scenarios provide a “most likely” starting point for refinements in sea-level forecasts that include ice flow dynamics.

6) Climate sensitivity to CO2:

3C for a doubling of CO2 is not a ‘conservative estimate,’ but the midpoint of the IPCC modelled scenarios which range from 1.1C to 6.4C. Climate models may well have a large positive feedback bias:

Potential Biases in Feedback Diagnosis from Observational Data: A Simple Model Demonstration by Roy W. Spencer and William D. Braswell. Journal of Climate, Volume 21, Issue 21 (November 2008) Article: pp. 5624-5628

Abstract
Feedbacks are widely considered to be the largest source of uncertainty in determining the sensitivity of the climate system to increasing anthropogenic greenhouse gas concentrations, yet our ability to diagnose them from observations has remained controversial. Here we use a simple model to demonstrate that any non-feedback source of top-of-atmosphere radiative flux variations can cause temperature variability which then results in a positive bias in diagnosed feedbacks. We demonstrate this effect with daily random flux variations, as might be caused by stochastic fluctuations in low cloud cover. The daily noise in radiative flux then causes interannual and decadal temperature variations in the model’s 50 m deep swamp ocean. The amount of bias in the feedbacks diagnosed from time-averaged model output depends upon the size of the non-feedback flux variability relative to the surface temperature variability, as well as the sign and magnitude of the specified (true) feedback. For model runs producing monthly shortwave flux anomaly and temperature anomaly statistics similar to those measured by satellites, the diagnosed feedbacks have positive biases generally in the range of ?0.3 to ?0.8 W m?2 K?1. These results suggest that current observational diagnoses of cloud feedback - and possibly other feedbacks - could be significantly biased in the positive direction.

I could go on, but it suffices to say that global warming seems to have stopped for now at least. There has been no warming trend since about 2001, and no increase in ocean heat content since 2003, despite rising CO2 emissions. We seem to have entered a cooling phase of the Pacific Decadal Oscillation (PDO) which should last to about 2030. Looking at the UAH Globally Averaged Satellite-Based Temperature (1979 - 2008), as Roy Spencer points out, “when one takes into consideration that the early 1990s cooling from the Mt. Pinatubo volcanic eruption and the warming from the 1997-98 El Nino warming event were not part of any underlying long-term trend, globally-averaged temperatures were flat from 1990 until 2000, then there was a brief warming until about 2002, after which temperatures have once again remained flat. Note that the longer temperatures remain flat the greater the warming that will be required to put us back ‘on track’ to match the climate model projections used by the U.N.’s Intergovernmental Panel on Climate Change.”

Regards,

Paul Biggs

Climate Research News

http://climateresearchnews.com/