Climate News from the science press

[bit_pattern]

Not really from the science press... But, an excellent report on greening rooves. Everything from decreasing the Urban Heat Island effect to increasing solar panel efficiency. Watch the video or read the transcript:

http://www.abc.net.au/catalyst/stories/2905009.htm

 

[macdoc]

Ocean heat content increases update
Filed under:

* Climate Science

— gavin @ 21 May 2010

There is a new paper in Nature this week on recent trends in ocean heat content from a large group of oceanographers led by John Lyman at PMEL. Their target is the uncertainty surrounding the various efforts to create a homogenised ocean heat content data set that deals appropriately with the various instrument changes and coverage biases that have plagued previous attempts.

We have discussed this issue a number of times because of its importance in diagnosing the long term radiative imbalance of the atmosphere. Basically, if there has been more energy coming in at the top than is leaving, then it has to have been going somewhere – and that somewhere is mainly the ocean. (Other reservoirs for this energy, like the land surface or melting ice, are much smaller, and can be neglected for the most part).

The main problem has been that over time the network of XBT probes and CTD casts has been replaced by the Argo float network which has a much greater coverage and more homogeneous instrumentation. However, connecting up the old and new networks, and dealing with specific biases in the XBT probes is difficult. An XBT (eXpendable Bathy-Thermograph) is a probe that is thrown off the ship and whose temperature readings as a function of time are transferred to a profile in depth from knowledge of how fast the probe falls. Unfortunately, this function is a complicated one that depends on the temperature of the water, the depth, the manufacturer of the probe etc. Various groups – working with the same basic data – have shown that there were biases in the XBT associated with incorrect calibrations and have attempted to make better corrections.

The latest paper is a consensus effort from many of the people involved in the previous work and shows how robust the recent decades warming of the ocean has been. Indeed, the ‘best estimate’ for the changes in the top 700m seems to be a greater warming than seen in the NODC data and more than even the models were suggesting:

more
http://www.realclimate.org/

 

[macdoc]

Did megafauna extinction cool the planet?
May 23rd, 2010 in Space & Earth / Earth Sciences

Mammoth exhibit at a museum. The rapid decline of mammoths and other megafauna after humans spread across the New World may explain a bone-chilling plunge in global temperatures some 12,800 years ago, researchers reported Sunday.

The rapid decline of mammoths and other megafauna after humans spread across the New World may explain a bone-chilling plunge in global temperatures some 12,800 years ago, researchers reported Sunday.
........
"We find that the loss of megafauna could explain 12.5 to 100 percent of the atmospheric decrease in methane observed," the researchers said. The theory is bolstered by the fact that the plunge in concentration was two-to-four times faster than the five other largest methane drops during the last 500,000 years, suggesting a unique confluence of factors. "The megafaunal extinction is the earliest catastrophic event attributed to human activity," the study concluded. "We thus propose that the onset of the 'Anthropocene' [epoch] should be recalibrated to 13,400 years before present, coincident with the first large-scale migrations of humans into the Americas."

http://www.physorg.com/print193847219.html

 

[macdoc]

Small mammals -- and rest of food chain -- at greater risk from global warming than thought
May 23, 2010 Small mammals -- and rest of food chain -- at greater risk from global warming than thought

The balance of biodiversity within North American small-mammal communities is so out of whack from the last episode of global warming about 12,000 years ago that the current climate change could push them past a tipping point, with repercussions up and down the food chain, say Stanford biologists. The evidence lies in fossils spanning the last 20,000 years that the researchers excavated from a cave in Northern California.

continues

http://www.physorg.com/news193846393.html

concludes

And according to Hadly, an extraordinarily rapid change is looming.
"The temperature change over the next hundred years is expected to be greater than the temperature that most of the mammals that are on the landscape have yet witnessed as a species," she said. "The small-mammal community that we have is really resilient, but it is headed toward a perturbation that is bigger than anything it has seen in the last million years."

 

[bit_pattern]

Greenland rises as ice melts

http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo845.html

Vertical motions of the rocky margins of Greenland and Antarctica respond to mass changes of their respective ice sheets1, 2. However, these motions can be obscured by episodes of glacial advance or retreat that occurred hundreds to thousands of years ago3, 4, 5, 6, which trigger a delayed response because of viscous flow in the underlying mantle. Here we present high-precision global positioning system (GPS) data that describe the vertical motion of the rocky margins of Greenland, Iceland and Svalbard. We focus on vertical accelerations rather than velocities to avoid the confounding effects of past events. Our data show an acceleration of uplift over the past decade that represents an essentially instantaneous, elastic response to the recent accelerated melting of ice throughout the North Atlantic region. Our comparison of the GPS data to models for glacial isostatic adjustment suggests that some parts of western coastal Greenland were experiencing accelerated melting of coastal ice by the late 1990s. Using a simple elastic model, we estimate that western Greenland’s ice loss is accelerating at an average rate of 8.7±3.5 Gt yr−2, whereas the rate for southeastern Greenland—based on limited data—falls at 12.5±5.5 Gt yr−2.

As explained on Skeptical Science

http://www.skepticalscience.com/Greenland-rising-faster-as-ice-loss-accelerates.html

 

[Complexity]

Lizards succumb to global warming

I heard a program on NPR's Science Friday recently about many species of reptiles suffering severe stress, some facing extinction, because of 2-degree (C?F?) temperature increases in places like Arizona.

I think this is the same story.

http://www.nature.com/news/2010/100513/full/news.2010.241.html

By 2080, global warming could result in one-fifth of the world's lizard species becoming extinct, a global study has found.

Even under the most optimistic scenarios for curbing carbon dioxide emissions, the analysis by an international team shows that one-fifth of the globe's lizard populations, corresponding to 6% of all lizard species, may go extinct by 2050.

"We've committed ourselves to that," says Barry Sinervo, an evolutionary biologist at the University of California, Santa Cruz, who led the study. He and his colleagues found that climate change has already driven 12% of the populations of Mexico's colourful Sceloporus lizards extinct since 1975.

If emissions continue at current levels, he predicts that by 2080, 39% of the world's lizard populations will have vanished, corresponding to a 20% loss in species. The study is published in Science this week1.

 

[Warmer1]

Lizards

"The problem, the team found, seems to be warmer springtimes, rather than higher maximum temperatures at midday or in midsummer.

Higher temperatures in spring mean that the animals spend less of the breeding season out foraging and more time in the shade. "That is the time of year that females need the maximum amount of food," says Huey. "If the temperature gets higher in the spring, then the lizards restrict their activity. They simply may not have enough active time to catch enough food."

Underfed females do not have the resources needed to make young, causing populations to crash."

I would have guessed higher maximum temperatures.

 

[lomiller]

Significant ocean warming over the last 16 years.

This one is interesting in that it’s a cooperative effort between a number of people who have looked at different parts of the question so it’s probably the most comprehensive study of ocean heat content yet.

http://www.nature.com/nature/journal/v465/n7296/full/nature09043.html


10^23J BTW is an incredible amount of energy

A large (~10^23 J) multi-decadal globally averaged warming signal in the upper 300 m of the world’s oceans was reported roughly a decade ago1 and is attributed to warming associated with anthropogenic greenhouse gases2, 3. The majority of the Earth’s total energy uptake during recent decades has occurred in the upper ocean3, but the underlying uncertainties in ocean warming are unclear, limiting our ability to assess closure of sea-level budgets4, 5, 6, 7, the global radiation imbalance8 and climate models5. For example, several teams have recently produced different multi-year estimates of the annually averaged global integral of upper-ocean heat content anomalies (hereafter OHCA curves) or, equivalently, the thermosteric sea-level rise5, 9, 10, 11, 12, 13, 14, 15, 16. Patterns of interannual variability, in particular, differ among methods. Here we examine several sources of uncertainty that contribute to differences among OHCA curves from 1993 to 2008, focusing on the difficulties of correcting biases in expendable bathythermograph (XBT) data. XBT data constitute the majority of the in situ measurements of upper-ocean heat content from 1967 to 2002, and we find that the uncertainty due to choice of XBT bias correction dominates among-method variability in OHCA curves during our 1993–2008 study period. Accounting for multiple sources of uncertainty, a composite of several OHCA curves using different XBT bias corrections still yields a statistically significant linear warming trend for 1993–2008 of 0.64 W m-2 (calculated for the Earth’s entire surface area), with a 90-per-cent confidence interval of 0.53–0.75 W m-2

 

[BenBurch]

And much greater than IPCC estimates... IPCC isn't wrong because it is alarmist, IPCC is wrong because it is minimizing.

 

[macdoc]

Excellent long article on ice ages and C02/orbital

http://www.newscientist.com/article...wn-why-ice-ages-dont-last-forever.html?page=1

 

[bit_pattern]

Great article, doc!

 

[macdoc]

sort of a companion piece

Scientists detect huge carbon 'burp' that helped end last ice age

May 27, 2010 Scientists have found the possible source of a huge carbon dioxide 'burp' that happened some 18,000 years ago and which helped to end the last ice age.



The results provide the first concrete evidence that carbon dioxide (CO2) was more efficiently locked away in the deep ocean during the last ice age, turning the deep sea into a more 'stagnant' carbon repository - something scientists have long suspected but lacked data to support.
Working on a marine sediment core recovered from the Southern Ocean floor between Antarctica and South Africa, the international team led by Dr Luke Skinner of the University of Cambridge radiocarbon dated shells left behind by tiny marine creatures called foraminifera (forams for short).

http://www.physorg.com/news194187137.html

 

[macdoc]

Published online 17 May 2010 | Nature | doi:10.1038/news.2010.238
News
Mediterranean most at risk from European heatwaves

Increased heat and humidity predicted to have biggest health impact in valleys and coastal cities.

http://www.nature.com/news/2010/170510/full/news.2010.238.html

snip

By 2100, the study finds, some parts of the area could experience 40 extremely warm days each year, compared with an average of just two between 1961 and 1990. Night-time temperatures above 20 °C and high relative humidity are likely to worsen the impact on health of extended heatwaves, the study warns.

Melbourne knows all about this....but not in 2100...in 2010

City's hot 100 smashes record for run of warm days

ADAM MORTON

March 19, 2010
MELBOURNE'S temperature has topped 20 degrees for the past 100 days straight, the longest stretch of its type in more than 150 years of measurement.
Yesterday's maximum of 31 degrees continued a run of 20-plus degree days that began on December 9 last year.

http://www.theage.com.au/environmen...ecord-for-run-of-warm-days-20100318-qid4.html

 

[bit_pattern]

Adelaide knows about it even better:

http://bravenewclimate.com/2009/11/14/three-record-heatwaves-seaust/

Time for some context. The closest Adelaide has ever come to a spring heat wave was 4 days in a row 1894. This month’s event will double that — a doubling like this is not twice as unlikely, it’s orders of magnitude more unlikely. Consider that in prior to 2008, the record length for an Adelaide heat wave in any month was 8 days (all occurring in summer). Now, in the space of less than 2 years, we’ve had a 15 day event in Mar 2008 (a 1 in 3000 year event), a 9 day sequence in Jan/Feb 2009 (which included 8 days above 40°C and 13 consecutive days above 33°C), and now, another 8 day event in Nov 2009. How unusual is this? There have been 6 previous heat waves that lasted 8 days, many more of 7 days, more still of 6, and so on — the return time is logarithmically related to it’s length. Given these data, and the fact that the latest spring event has equaled previous all-time summer records (!), and the alarm bells should rightly be ringing. Statistically speaking, it’s astronomically unlikely that such a sequence of rare heat waves would occur by chance, if the climate wasn’t warming. But of course, it is.

And more on the subject:

http://bravenewclimate.com/2009/02/03/is-there-a-link-between-adelaides-heatwave-and-global-warming/

Call me an alarmist, but living in SE Australia truly is alarming.

 

[macdoc]

1/10th of a degree..

A cooler Pacific may have severely affected medieval Europe, North America
June 9, 2010

In the time before Columbus sailed the ocean blue, a cooler central Pacific Ocean has been connected with drought conditions in Europe and North America that may be responsible for famines and the disappearance of cliff dwelling people in the American West.

http://www.physorg.com/news195309866.html

good read

 

[macdoc]

Sea Levels May Rise by as Much as One Meter Before the End of This Century

ScienceDaily (June 10, 2010) — Sea levels may rise by as much as one metre before the end of this century, according to new predictions. Melting glaciers may contribute more to the rise in sea levels than scientists have previously realised.

http://www.sciencedaily.com/releases/2010/06/100610095043.htm
more

 

[macdoc]

NASA: Easily the hottest spring — and Jan-May — in temperature record

Plus another record 12-month global temperature

June 10, 2010
Lmonth tied May 1998 as the hottest on record in the NASA dataset. More significantly, following fast on the heels of easily the hottest April — and hottest Jan-April — on record, it’s also the hottest Jan-May on record [click on figure to enlarge].
Also, the combined land-surface air and sea-surface water temperature anomaly for March-April-May was 0.73°C above the 1951-1980 mean, blowing out the old record of 0.65°C set in 2002.
The record temperatures we’re seeing now are especially impressive because we’ve been in “the deepest solar minimum in nearly a century.
........
Most significantly, the 12-month global temperature grew to 0.66°C — easily the highest on record.

http://climateprogress.org/

 

[macdoc]

Intensive farming 'massively slowed' global warming

• 20:00 14 June 2010 by Andy Coghlan

Fertilisers, pesticides and hybrid high-yielding seeds saved the planet from an extra dose of global warming. That, at least, is the conclusion of a new analysis which finds that the intensification of farming through the green revolution has unjustly been blamed for speeding up global warming.

http://www.newscientist.com/article/dn19042-intensive-farming-massively-slowed-global-warming.html

 

[macdoc]

Science News

Rapid Changes for Arctic Flora and Fauna

ScienceDaily (June 9, 2010) — Unique Arctic habitats for flora and fauna, including sea ice, tundra, lakes, and peatlands have been disappearing over recent decades, and some characteristic Arctic species have shown a decline. The changes in Arctic Biodiversity have global repercussions and are further creating challenges for people living in the Arctic

http://www.sciencedaily.com/releases/2010/06/100609094134.htm

what was that.....4 SD?? ..

 

[Furcifer]

You missed this one:

More Cold and Snowy Winters to Come in Europe, Eastern Asia and Eastern North America

A warmer Arctic climate is influencing the air pressure at the North Pole and shifting wind patterns on our planet. We can expect more cold and snowy winters in Europe, eastern Asia and eastern North America.

full story here

That's right folks, Global Warming means "Cold and snowy winters will be the rule, rather than the exception," says Dr James Overland of the NOAA/Pacific Marine Environmental Laboratory in the United States.