Quenching forest fires leads to more carbon in the air, says new research carried out in Californian forests. The discovery suggests that forests spared from fire may release more of the greenhouse gas into the air than they absorb.
Decades of suppressing natural fires has increased the number of surviving trees in California’s forests. But this growth has been at the expense of larger trees, which are less resilient to drought and other stresses than smaller, younger trees, resulting in a decline in the total amount of carbon stored in these forests.
Nature News.com: Forest-fire management ‘raises carbon emissions’
Governments should work together to build the supercomputers needed for future predictions that can capture the detail required to inform policy.
Few scientific creations have had greater impact on public opinion and policy than computer models of Earth’s climate. These models, which unanimously show a rising tide of red as temperatures climb worldwide, have been key over the past decade in forging the scientific and political consensus that global warming is a grave danger.
Now that that consensus is all but universal, climate modellers are looking to take the next step, and to convert their creations from harbingers of doom to tools of practical policy. That means making their simulations good enough to guide hard decisions, from targets for carbon dioxide emissions on a global scale to the adaptations required to meet changing rainfall and extreme weather events on regional and local scales.
Today’s modelling efforts, though, are not up to that job. They all agree on the general direction in which the climate will move as greenhouse gases build up, but they do not reliably capture all the nuances of today’s climate, let alone tomorrow’s. Moreover, each model differs from reality in different ways.
Editorial: The next big climate challenge
Methane outbursts from seafloor deposits are unlikely to have been the sole cause of an extreme episode of global warming around the time of the Palaeocene–Eocene Thermal Maximum some 55 million years ago.
Research Highlights: Palaeoclimate: Methane didn’t act alone
Data laboriously extracted from an Antarctic ice core provide an unprecedented view of temperature, and levels of atmospheric carbon dioxide and methane, over the past 800,000 years of Earth’s history.
The data further reinforce the tight link between greenhouse gases and climate, a link maintained by as-yet only partially understood feedbacks in the Earth system. Variations in methane levels are most probably caused by variations in the influence of temperature and rainfall on wetlands in the tropics and boreal (high-northern-latitude) regions. Carbon dioxide variability is almost universally viewed as an oceanic phenomenon, a consequence of the large pools of carbon sequestered there. Changes in ocean circulation, biological productivity, carbon dioxide solubility and other aspects of ocean chemistry have been implicated, but the exact mix of mechanisms is not clear.
News and Views: Palaeoclimate: Windows on the greenhouse
The climate is changing, and so are aspects of the world’s physical and biological systems. It is no easy matter to link cause and effect — the latest attack on the problem brings the power of meta-analysis to bear. It uses a larger database than the recent IPCC report, and it takes account of land-use change and other complications. The authors conclude that anthropogenic climate change is affecting physical and biological systems globally. But as Francis Zwiers and Gabriele Hegerl point out in News & Views, this proof based on the principle of joint attribution stops short of the statistical certainty that would be provided by ‘end-to-end’ models linking human activity directly to the observed changes, rather than via effects on the climate system.
News and Views: Climate change: Attributing cause and effect
Significant changes in physical and biological systems are occurring on all continents and in most oceans, with a concentration of available data in Europe and North America. Most of these changes are in the direction expected with warming temperature. Here we show that these changes in natural systems since at least 1970 are occurring in regions of observed temperature increases, and that these temperature increases at continental scales cannot be explained by natural climate variations alone. Given the conclusions from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report that most of the observed increase in global average temperatures since the mid-twentieth century is very likely to be due to the observed increase in anthropogenic greenhouse gas concentrations, and furthermore that it is likely that there has been significant anthropogenic warming over the past 50 years averaged over each continent except Antarctica, we conclude that anthropogenic climate change is having a significant impact on physical and biological systems globally and in some continents.
Article: Attributing physical and biological impacts to anthropogenic climate change
Changes in past atmospheric carbon dioxide concentrations can be determined by measuring the composition of air trapped in ice cores from Antarctica. So far, the Antarctic Vostok and EPICA Dome C ice cores have provided a composite record of atmospheric carbon dioxide levels over the past 650,000 years1, 2, 3, 4. Here we present results of the lowest 200 m of the Dome C ice core, extending the record of atmospheric carbon dioxide concentration by two complete glacial cycles to 800,000 yr before present. From previously published data1, 2, 3, 4, 5, 6, 7, 8 and the present work, we find that atmospheric carbon dioxide is strongly correlated with Antarctic temperature throughout eight glacial cycles but with significantly lower concentrations between 650,000 and 750,000 yr before present. Carbon dioxide levels are below 180 parts per million by volume (p.p.m.v.) for a period of 3,000 yr during Marine Isotope Stage 16, possibly reflecting more pronounced oceanic carbon storage. We report the lowest carbon dioxide concentration measured in an ice core, which extends the pre-industrial range of carbon dioxide concentrations during the late Quaternary by about 10 p.p.m.v. to 172–300 p.p.m.v.
Letter: High-resolution carbon dioxide concentration record 650,000–800,000 years before present
Atmospheric methane is an important greenhouse gas and a sensitive indicator of climate change and millennial-scale temperature variability1. Its concentrations over the past 650,000 years have varied between 350 and 800 parts per 109 by volume (p.p.b.v.) during glacial and interglacial periods, respectively2. In comparison, present-day methane levels of 1,770 p.p.b.v. have been reported3. Insights into the external forcing factors and internal feedbacks controlling atmospheric methane are essential for predicting the methane budget in a warmer world3. Here we present a detailed atmospheric methane record from the EPICA Dome C ice core that extends the history of this greenhouse gas to 800,000 yr before present. The average time resolution of the new data is 380 yr and permits the identification of orbital and millennial-scale features. Spectral analyses indicate that the long-term variability in atmospheric methane levels is dominated by 100,000 yr glacial–interglacial cycles up to 400,000 yr ago with an increasing contribution of the precessional component during the four more recent climatic cycles. We suggest that changes in the strength of tropical methane sources and sinks (wetlands, atmospheric oxidation), possibly influenced by changes in monsoon systems and the position of the intertropical convergence zone, controlled the atmospheric methane budget, with an additional source input during major terminations as the retreat of the northern ice sheet allowed higher methane emissions from extending periglacial wetlands. Millennial-scale changes in methane levels identified in our record as being associated with Antarctic isotope maxima events1, 4 are indicative of ubiquitous millennial-scale temperature variability during the past eight glacial cycles.
Letter: Orbital and millennial-scale features of atmospheric CH4 over the past 800,000 years
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
The Nature item “Attributing physical and biological impacts to anthropogenic climate change” had a good run on ABC radio today.
One commentator; David Karoly reckoned there was very little science from number of important places including Australia and our MDB in particular. “Patchy” R & D.
See ABC “Scientists lament lack of Aust climate change research –
Australia has only ‘patchy records’ on the water-starved Murray-Darling Basin. (Lew Wray)
Around the world, glaciers are melting, flowers are blooming out of season and hibernating animals are waking up earlier than they used to.
A report in the journal Nature suggests human-induced climate change is having an impact on the natural environment much earlier than scientists had predicted.
But while the evidence from North America and Europe is overwhelming, there is a gap in the research coming from Australia”
http://www.abc.net.au/news/stories/2008/05/15/2246085.htm?section=australia
http://www.nature.com/nature/journal/v453/n7193/abs/nature06937.html
Seek and ye shall find. What about a winter visitor that arrives a month early?
On the coldest day I’ve ever encountered for April [last month] I saw a rose robin?
Get enough people running around looking for things and they’re bound to turn up.
Anyone have a complete copy of the Nature paper that claims to have found evidence of human activity in warming?
From what I’ve read the reviewers included the two coordinating lead authors of the IPCC WG I chapter in which it was claimed that human activity has influenced climate.
– If the IPCC 4AR claimed this as a fact then why is it being claimed that this paper shows the first proof.
– What were the realistic chances of a harsh or even balanced review from these two?
As usual, the claim seems to rest on “we don’t know what natural forces could have caused the increase in temperature so therefore it must be human”. This is a joke.
The sustained semi-El Nino from 2002 could have caused the slight warming and the shift in cloud cover since 1999 (less low cloud, more mid-level in the 20-90 degrees latitude regions) should account for the flora and fauna responding earlier to spring-like conditions.
The whole claim reeks of desperate moves to sustain an industry in the face of temperatures that have fallen because of a La Nina.
How utterly hilarious – yes due to La Nina they just whipped up a quick review of 30000 biological studies over 50 years.
And yes they also discussed CO2 effects, land use change, seasonal oscillations – but large numbers of studies over a long period over the northern hemisphere show changes in phenology and behaviour suggesting the world has warmed up. Big numbers over wide areas over time. Is that such a shock?
“Observed responses to climate change are found across a wide
range of systems as well as regions. Changes related to regional
warming have been documented primarily in terrestrial biological
systems, the cryosphere and hydrologic systems; significant changes
related to warming have also been studied in coastal processes,
marine and freshwater biological systems, and agriculture and
forestry (Fig. 1). In each category, many of the data series are over
35 years in length.
Responses in physical systems include shrinking glaciers in every
continent3,4, melting permafrost5,6, shifts in the spring peak of river
discharge associated with earlier snowmelt7,8, lake and river warming
with effects on thermal stratification, chemistry and freshwater
organisms9–11, and increases in coastal erosion12–14. In biological
systems, changes include shifts in spring events (for example, leaf
unfolding, blooming date, migration and time of reproduction),
species distributions and community structure15–18. Additionally,
studies have demonstrated changes in marine-ecosystem functioning
and productivity, including shifts from cold-adapted to warm adapted
communities, phenological changes and alterations in
species interactions”
I imagine a large denialist effort will now have to invested in bleating little excuses why it’s all wrong. This will be a hoot.
I have no time yet to sort through this, but if it is sustainable it is of great interest
http://www.nature.com/nature/journal/v453/n7193/full/453291a.html
Very impressive Alarmist – goodness me how erudite you are!
So here goes on the “hoot”
In all those words I see lots of what could be attributed to increased temperatures (climate change) but where is the evidence that these observed changes are man made?
And if you are not addressing the “man made” issue what is your point?
BTW I believe there is plausible empirical evidence that global temperatures have increased since about 1975 but that the same evidence shows that there is little or no increase since about 2000. And I have yet to find any convincing evidence that such temperature increases are due to increases in atmospheric CO2 concentration.
C’mon Luke, this is the same old, same old.
Just more people involved with the same lack of objectivity.
And the climate, she is a changin’.
Due to how many reasons, do you think?
Why get overly excited – just shows the global biology has responded to a warming trend. Simple point. Comprehensive data. Lots of studies.
Arguing the anthropogenic impact is another thread.
But clearly climate changes – even small ones like we have had to date – cause noticeable effects. Face it – there is not one paper that would ever be written that could convince you guys. Not one. There will always be a “but but but but …”
So why even respond?
But if the climate is a changin’ – why? Is the Sun changing significantly – I don’t think so….
Okay, here is the ten year temperature record updated to April. As you can see the trend is dead flat for UAH and HadCrut3, and slightly down for RSS.
http://tinyurl.com/4de3v7
“Okay, here is the ten year temperature record updated to April”.
Careful Tilo. You’ll get Lukey boy whinging on about hand drawn graphs!
Yep – but extend your graph back a few decades. Don’t be sneaky and start the clock at 1998. The paper is simply saying over the broader span of time there have been biological effects of the overall warming experienced.
And yep no problem acknowledging that the recent time period is flat. Quite interesting – we’ll see what happens in the next few years.
The Karoly paper just shows the recent little warming phase from 1970 to 2000 caused some melting and changes in fauna and flora. There is nothing new in it to support anthropogenic effects.
Luke, is Jaworoski’s theory on CO2 and other atmo gasses in ice cores being nigh impossible to measure accurately, accurate?
Or has the problem been solved?
Drongo, they don’t even accept that there might be a problem, that there might even be a grain of truth in what J has said.
I haven’t seen anything since http://www.someareboojums.org/blog/?p=7 and
http://www.someareboojums.org/blog/?p=18
Ice core drilling must be murderously difficult when it comes to extracting accurate forensic evidence at these depths.
You are not STILL flogging that bojums bollocks are you Lord Creepo? it is nothing but a second rate undergrad sneer session masquerading as analysis. Give us a break.
Pathetic Mottsa. Lots of specific technical comment. Did you read both – or course not.
Yes I did read them Lord Creepo and all I saw was a bunch of cheap shots dressed in pseudo science drag.
tilo its doesnt matter how many graphs you show these guys according to them temperatures are going up forever