Wednesday, September 28, 2016
Earth is warmer that it has been in 120,000 years - and is 'locked in' to hit its hottest mark in more than 2 million years, study claims
Amusing stuff. The paper I led with yesterday sets out why it is too difficult to get accurate parameter estimates from paleoclimate data. So this study is basically just a huge exercise in guesswork. I have always been critical of paleoclimte estimates derived from ice-cores, tree rings etc. so would always have rubbished this study. As it happens however, even some prominent Warmists have dismissed the study as incapable of giving accurate estimates of anything. See the next article below this one
A new study paints a picture of an Earth that is warmer than it has been in about 120,000 years, and is locked into eventually hitting its hottest mark in more than 2 million years.
As part of her doctoral dissertation at Stanford University, Carolyn Snyder , now a climate policy official at the U.S. Environmental Protection Agency, created a continuous 2 million year temperature record, much longer than a previous 22,000 year record.
Snyder's temperature reconstruction, published Monday in the journal Nature , doesn't estimate temperature for a single year, but averages 5,000-year time periods going back a couple million years.
Carolyn Snyder uses a network of over 20,000 sea surface temperature reconstructions from 59 ocean sediment cores to reconstruct GAST for the past two million years at 1,000-year intervals.
Snyder based her reconstruction on 61 different sea surface temperature proxies from across the globe, such as ratios between magnesium and calcium, species makeup and acidity.
But the further the study goes back in time, especially after half a million years, the fewer of those proxies are available, making the estimates less certain, she said.
These are rough estimates with large margins of errors, she said.
But she also found that the temperature changes correlated well to carbon dioxide levels.
Temperatures averaged out over the most recent 5,000 years — which includes the last 125 years or so of industrial emissions of heat-trapping gases — are generally warmer than they have been since about 120,000 years ago or so, Snyder found.
And two interglacial time periods, the one 120,000 years ago and another just about 2 million years ago, were the warmest Snyder tracked.
They were about 3.6 degrees (2 degrees Celsius) warmer than the current 5,000-year average.
With the link to carbon dioxide levels and taking into account other factors and past trends, Snyder calculated how much warming can be expected in the future.
Snyder said if climate factors are the same as in the past — and that's a big if — Earth is already committed to another 7 degrees or so (about 4 degrees Celsius) of warming over the next few thousand years.
'This is based on what happened in the past,' Snyder said. 'In the past it wasn't humans messing with the atmosphere.'
Scientists give various reasons for past changes in carbon dioxide and heat levels, including regular slight shifts in Earth's orbital tilt.
Mann and Schmidt on Snyder's 2 million year study
The study estimates what is known as the "Earth system sensitivity," which encompasses a variety of feedbacks within the climate system, from the response of the atmosphere and oceans to fluctuations in greenhouse gases to the ways that ice sheet expansion or melting can alter global temperatures.
However, this metric is a correlation between events, and doesn't pinpoint whether one event caused another. Still, the study estimates an Earth system sensitivity of 9 degrees Celsius, or 16.2 degrees Fahrenheit, per a doubling of atmospheric carbon dioxide levels over millennium timescales.
In more simple terms, this means that over the long, long-term, our planet will see its global average surface temperature increase by up to 9 degrees Celsius if greenhouse gases in the atmosphere were to double, which they are currently on course to do.
The study found that if all greenhouse gas emissions were to cease today, the climate would still warm by about 5 degrees Celsius, or 9 degrees Fahrenheit, during the next several centuries.
However, the Earth system sensitivity metric is not the same as the similarly named, but altogether different, scientific metric known as climate sensitivity. That metric is defined as how much the globe would warm if greenhouse gas concentrations in the atmosphere were to double.
Climate sensitivity considers the influence of greenhouse gases, such as carbon dioxide, alone, while Earth system sensitivity involves a variety of feedbacks between the land, oceans and atmosphere, some of which are not well understood.
With climate sensitivity, carbon dioxide and other greenhouse gases are in the driver’s seat, whereas with Earth system sensitivity, there are many drivers, with cars going in different directions and sometimes colliding head on.
Estimates of climate sensitivity tend to be much lower than 9 degrees Celsius, closer to about 3 degrees Celsius.
The problem, Snyder as well as several outside scientists told Mashable, is that it's not clear exactly what was driving temperature changes during some time periods in the past.
"[Earth system sensitivity] is a useful metric that summarizes a combination of interactive feedbacks in the climate system (including temperature, greenhouse gases, ice sheets, vegetation, and dust)," Snyder said in an email.
"But it is a correlation observed in the past, not a test of causation," she said.
Michael Mann, a climate researcher at Penn State University who has published influential studies on the planet's climate history, said he views the new study as "somewhat of an outlier." Mann was not involved in the new research.
"The estimate of earth system sensitivity (9C for CO2 doubling) is so much higher than the prevailing estimates (5-6C) that one has to consider it somewhat of an outlier, and treat it with an appropriate level of skepticism," he told Mashable in an email.
One major problem with the study, Mann said, is that the sensitivity estimate is dominated by glacial and interglacial cycles during the past 800,000 years, and it's tough to untangle the roles played by carbon dioxide in such variations.
This is because carbon dioxide both causes and responds to temperature changes that are driven by other factors, such as variations in Earth's orbit around the sun.
"It is unclear that an estimate of the relationship between global temperature and carbon dioxide under those circumstances is an appropriate measure of the response of temperature when carbon dioxide alone is the major driving force, as it true today," Mann said.
"So I regard the study as provocative and interesting, but the quantitative findings must be viewed rather skeptically until the analysis has been thoroughly vetted by the scientific community."
Gavin Schmidt, a climate scientist who directs NASA's Goddard Institute for Space Studies in New York, was more blunt in his views on the new publication.
"The temperature reconstruction is great, but the claims about sensitivity are just wrong," Schmidt, who was not involved in the new research, said in an email. "This is not an argument about methods or what to present in public or whether you like models or observations, it is just wrong."
Where is Earth's oxygen going? Vital gas has vanished from the atmosphere over the past 800,000 years leaving experts baffled
There is no puzzle here. The only puzzle is why some people think they can use paleoclimate data to make such precise estimates
Something strange is going on with the planet’s oxygen levels, which has left researchers scratching their heads as to the cause.
Scientists testing the concentration of oxygen in the atmosphere have found that levels have dropped by almost 0.7 per cent over the past 800,000 years, compared to modern levels.
What’s more, the rate of this decline has sped up over the last century, dropping by a further 0.1 per cent.
Oxygen levels currently stand at around 21 per cent, but have fluctuated greatly over the planet’s 4.3 billion-year history, with two major spikes linked with the explosion of life.
To sample the ancient atmosphere, a team led by researchers at Princeton University in New Jersey, studied bubbles of gas frozen in the ice of Greenland and Antarctica thousands of years ago.
By measuring changes in the atmospheric concentrations of oxygen and nitrogen, they showed a subtle declining trend over thousands of years.
The researchers believe that burning fossil fuels has led to the rapid increase seen over the last century – by consuming oxygen and releasing large quantities of carbon dioxide into the atmosphere – but the cause of the longer term decline has been trickier to pin down.
One potential explanation put forward by the scientists for the declining oxygen in the recent geological past is an increase in erosion, which would lead to freshly exposed sediment being oxidised by the atmosphere, reducing atmospheric oxygen levels.
Another long term process which is interaction with the oceans. With lower average global temperatures in the past, the world’s oceans would have been able to absorb more oxygen, with cooler waters able to soak up more gas.
The researchers believe a series of slow chemical reactions between the atmosphere and rocks, known as silicate weathering, could explain the apparent lack of carbon dioxide in the atmosphere.
Unlike the recent decline, there is no evidence to suggest carbon dioxide levels increased substantially during the period.
But the researchers believe a series of slow chemical reactions between the atmosphere and rocks, known as silicate weathering, could explain this lack of carbon dioxide.
‘The planet has various processes that can keep carbon dioxide levels in check,’ said Dr Daniel Stolper, a geoscientist at Princeton.
Over thousands of years, carbon dioxide in the atmosphere reacts with exposed rock to form calcium carbonate minerals, trapping the carbon in a solid form. In geological timescales, this process soaks up atmospheric carbon, locking it away in rock.
Scientists believe that as more carbon dioxide has been released into atmosphere from burning fossil fuels, the increasing temperature has led to the weathering process occurring more rapidly.
But human activity is releasing carbon dioxide into the atmosphere so quickly that we may cause this slow, long-term geological process to ‘short-circuit’, and so they cannot keep up.
One potential explanation put forward for the declining oxygen in the recent geological past is an increase in erosion, which would lead to freshly exposed sediment being oxidised by the atmosphere, reducing atmospheric oxygen levels.
Another long term process to factor in is interaction with the oceans.
With lower average global temperatures in the past, the world’s oceans would have been able to absorb more oxygen, as cooler waters able to soak up more gas.
‘This record represents an important benchmark for the study of the history of atmospheric oxygen,’ said Dr John Higgins, co-author of the study.
‘Understanding the history of oxygen in Earth’s atmosphere is intimately connected to understanding the evolution of complex life. It’s one of these big, fundamental ongoing questions in Earth science’
The findings were published recently in the journal Science.
Could you really catch a tropical disease on UK SHORES? Experts warn global warming may create ideal conditions for deadly diseases on our very doorsteps
I can see no chance of Britain ever being warm enough for tropical diseases to flourish there but let's play the game and see what a warmer Britain would imply. It would imply very little. I was born and bred in the tropics amid a population derived overwhelmingly from the British Isles. So did we all die of disease? Far from it. As far as I can see were as healthy as anyone else.
We did have such tropical nasties as Ross River fever and Dengue fever endemic among us but for most of us attacks of them were just another cold or flu. And when the kids in my class at school were given the Mantoux skin test all but one of us tested positive -- meaning we had all had TB without realizing but had thrown it off. Reality sure beats theory, doesn't it?
Cold is the big health hazard so our warm environment presumably kept us healthy despite bacterial and viral challenges. A tropical Britain should fare similarly
Britain may be chilly, but at least a trip to the seaside here is unlikely to leave you with anything more serious than an ear infection.
But could that change? Last week it was reported that some experts fear Britain is on course to be warmer and wetter as global temperatures rise.
According to a report from the Department of Health, Health Effects Of Climate Change In The UK, British winters will become less cold but wetter, whereas summers will become warmer and probably drier in some places.
Some warn that these changes could create ideal conditions for some of the world’s most unpleasant and deadlier diseases to get a hold in the Mediterranean and even the UK.
These include cholera and zika, which is linked to microcephaly (a devastating brain defect) in babies.
And a study, Explaining Ocean Warming, published this month by the International Union for Conservation of Nature suggested that a form of tropical food poisoning known as ciguatera — caused by eating fish that have consumed toxins released in seawater by algae — could soon be common around the UK’s coastline.
Water temperatures on the South Coast in July and August are already edging up to the 15c needed to support a bloom of the algae.
Warmer temperatures ‘will have far reaching effects on a whole range of public health in the UK’, says Dr Nick Watts, director of the UK Health Alliance on Climate Change.
‘This includes increased risk of water-borne diseases across Europe such as cholera, as well as those that are carried by insects that thrive in warmer temperatures.’
The real lesson from South Australia’s electricity ‘crisis’: we need better climate policy
The guy below is certainly right about that but he waffles a lot and is very timid about saying exactly what policy is needed. He knows perfectly well what is needed if big spikes in power prices are to be avoided: Backup generators fired by coal (cheapest) or natural gas (dearest). And only government subsidies will keep them available. Once you distort the market by subsidizing one source of power, you have to subsidize the rest of the market too. Otherwise your backup generators will go out of business, which is what happened in South Australia
Australia’s energy markets got a big shock in July this year, when wholesale electricity prices spiked in South Australia, alarming the state government and major industrial customers. Commentators rushed to find the immediate culprits. But the real issues lie elsewhere.
As shown by the Grattan Institute’s latest report the market worked. Having soared, prices fell back to more manageable levels. The lights stayed on.
Yet South Australia’s power shock exposed a looming problem in Australia’s electricity system – not high prices or the threat of blackouts, but an emerging conflict between Australia’s climate change policies and the demands of our energy market.
A perfect storm
On the evening of July 7, the wind wasn’t blowing, the sun wasn’t shining, and the electricity connector that supplies power from Victoria was down for maintenance. This meant gas set the wholesale price, and gas is expensive these days, especially during a cold winter. At 7.30pm wholesale spot prices soared close to A$9,000 per megawatt hour. For the whole month they averaged A$230 a megawatt hour. They were closer to A$65 in the rest of the country.
Australia has committed to a target to reduce greenhouse gas emissions by 26-28% below 2005 levels by 2030. Despite this well known and significant target, the national debate on climate change has been so toxic and so destructive that almost no policy remains to reduce emissions from the power sector in line with that target.
By 2014 the much maligned renewable energy target (RET), a Howard government industry policy to support renewable energy, remained as the only policy with any real impact on the sector’s emissions.
Wind power has been the winning technology from the RET, and South Australia has been the winning state. Wind now supplies 40% of electricity in South Australia due to highly favourable local conditions. Because wind has no fuel costs it suppressed wholesale prices in the state and forced the shutdown of all coal plants and the mothballing of some gas plants. But wind is intermittent – it generates power only when it is blowing, and the night of July 7 it barely was.
A report by the Australian Energy Market Operator noted that the market did deliver on reliability and security of supply in July. It reviewed the behaviour of market participants and concluded there were “no departures from normal market rules and procedures”.
The events of July do not expose an immediate crisis, but they have exposed the potential consequences of a disconnection between climate change policy and energy markets. If it is not addressed, the goals of reliable, affordable and sustainable energy may not be achieved.
The bigger problem
Climate change policy should work with and not outside the electricity market. With a fixed generation target of 33,000 gigawatt hours of renewable electricity by 2020 and a market for renewable energy credits outside the wholesale spot market under the RET, the conditions for problems were established some time ago.
The specific issues that arose from the design of the RET would have been far less problematic if one of the attempts over the last ten years to implement a national climate policy had been successful. A rising carbon price would have steadily changed the relative competitiveness of high and low emissions electricity sources and the RET would have quietly faded.
The first lesson for governments is that we need to establish a credible, scalable and predictable national climate change policy to have a chance of achieving emissions reduction targets without compromising power reliability or security of supply. A national emissions trading scheme would be best, but pragmatism and urgency mean we need to consider second best.
While such an outcome is the first priority, it will not provide all the answers. The rapid introduction of a very large proportion of new intermittent electricity supply creates problems that were not foreseen when traditional generation from coal and gas supplied the bulk of Australia’s power needs.
All of the wind farms in one state could be offline at the same time – a far less likely event with traditional generation. The problem can be solved by investment in storage and in flexible responses such as gas and other fast-start generators. Commercial deals with consumers paid to reduce demand could also contribute.
Lower average prices combined with infrequent big price spikes are not an obvious way to encourage long-term investors. The market may find solutions with new forms of contracts for flexibility or the market operator could introduce new structures or regulations to complement the existing wholesale spot market.
Much uncertainty exists, no easy fixes are in sight and the consequences of failure are high. Getting it right will provide clear signals for new investment or for withdrawal of coal plants as flagged by speculation over the future of the Hazelwood power station in Victoria.
Josh Frydenberg, as the new minister for the environment and energy, and his fellow ministers on the COAG Energy Council would be unwise to waste a near crisis.
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Posted by JR at 1:33 AM