Peak fossil fuels means global warming less than projected

Posted on July 15, 2013 by

This Science article states we could emit CO2 at the same rate we are now for another 50 years before going over the 2 degrees Celsius level we need to avoid a runaway greenhouse.  Since we are at peak world fossil fuels now (oil since 2005, coal right now energy-content-wise) or within the 10-20 years (coal, natural gas) — the decline of which will likely create enough war and social unrest to prevent extraction of most other fossil fuels, there’s an excellent chance we are on the cusp of a permanent decline in fossil fuel emissions, as well as a reduction of damage in the 9 planetary boundaries, since fossil fuels are the master resource that make the damage we’re doing to the planet possible.

H. Damon Matthews Science 26 April 2013: Vol. 340 no. 6131 pp. 438-439   DOI: 10.1126/science.1236372

Irreversible Does Not Mean Unavoidable

Understanding how decreases in CO2 emissions would affect global temperatures has been hampered in recent years by confusion regarding issues of committed warming and irreversibility. The notion that there will be additional future warming or “warming in the pipeline” if the atmospheric concentrations of carbon dioxide were to remain fixed at current levels has been misinterpreted to mean that the rate of increase in Earth’s global temperature is inevitable, regardless of how much or how quickly emissions decrease. Further misunderstanding may stem from recent studies showing that the warming that has already occurred as a result of past anthropogenic carbon dioxide increases is irreversible on a time scale of at least 1000 years. But irreversibility of past changes does not mean that further warming is unavoidable.

The climate responds to increases in atmospheric CO2 concentrations by warming, but this warming is slowed by the long time scale of heat storage in the ocean, which represents the physical climate inertia. There would indeed be unrealized warming associated with current CO2 concentrations, but only if they were held fixed at current levels.

If emissions decrease enough, the CO2 level in the atmosphere can also decrease.

My comment: The CO2 level in the atmosphere will go down from now on because we’re at peak oil, coal, and natural gas production — or will be soon.

This potential for atmospheric CO2 to decrease over time results from inertia in the carbon cycle associated with the slow uptake of anthropogenic CO2 by the ocean. This carbon cycle inertia affects temperature in the opposite direction from the physical climate inertia and is of approximately the same magnitude.

Because of these equal and opposing effects of physical climate inertia and carbon cycle inertia, there is almost no delayed warming from past CO2 emissions. If emissions were to cease abruptly, global average temperatures would remain roughly constant for many centuries, but they would not increase very much, if at all. Similarly, if emissions were to decrease, temperatures would increase less than they otherwise would have.

Thus, although the CO2-induced warming already present on our planet—the cumulative result of past emissions—is irreversible, any further increase in CO2-induced warming is entirely the result of current CO2 emissions. Warming at the end of this century and beyond will depend on the cumulative emissions we emit between now and then. But future warming is not unavoidable: CO2 emissions reductions would lead to an immediate decrease in the rate of global warming.

Why, then, are many different near-term projections of CO2-induced warming very similar? These modeled estimates are similar because even socioeconomic scenarios that produce very different cumulative emissions by the end of this century are not very different over the next two decades (figs. S1 and S2). The climate system physics implies that further increases in warming could in principle be stopped immediately, but human systems have longer time scales. Carbon-emitting infrastructure is designed to benefit human-kind for many decades; each year’s additional infrastructure implies added stock intended to last and emit CO2 for many decades. It is this dependence on CO2-emitting technology that generates a commitment to current and near-future emissions.

The strong dependence of future warming on future cumulative carbon emissions implies that there is a quantifiable cumulative amount of CO2 emissions that we must not exceed if we wish to keep global temperature below 2°C above preindustrial temperatures. Several recent analyses have suggested that total CO2 emissions of ∼1000 Pg C (∼3700 Pg CO2; 1 Pg = 1015 g) would give us about even odds of meeting the 2°C target (9–12). To meet such a target given historical emissions would mean that the world has roughly half of the allowable emissions budget remaining. This is equivalent to 50 years of emissions at current levels and carries the implication that the longer we delay before beginning to decrease emissions, the faster the rate of decrease must be to stay within this total allowable budget.

Given the irreversibility of CO2-induced warming, every increment of avoided temperature increase represents less warming that would otherwise persist for many centuries. Although emissions reductions cannot return global temperatures to pre-industrial levels, they do have the power to avert additional warming on the same time scale as the emissions reductions themselves. Climate warming tomorrow, this year, this decade, or this century is not predetermined by past CO2 emissions; it is yet to be determined by future emissions. The climate benefits of emissions reductions would thus occur on the same time scale as the political decisions that lead to the reductions.

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Stephen Hawking: Escape to another planet before we go extinct

Posted on July 15, 2013 by

The only method of propulsion we have to escape the planet is, you guessed it, fossil fuels, and they don’t come anywhere near to getting us to the speed of light necessary to get to even the closest star. Nor will a space elevator do that — even if it could be built, it’s absolutely ridiculous to think we could survive on the Moon or Mars.  Even Biosphere II was a failure, and that was right here on Earth.   The idea of abandoning Earth is absurd, ridiculous, sad — pure science-fiction.  But you can’t talk about extinction, or get a book published if you don’t offer some hope.

Stephen Hawking believes we won’t survive another 1,000 years unless we escape Mother earth.  He believes people will become extinct by then if we don’t.  “I believe that the long-term future of the human race must be in space, since it will be difficult enough to avoid disaster on planet Earth in the next hundred years, let alone the next thousand, or million. The human race shouldn’t have all its eggs in one basket, or on one planet.  In the recent past, humankind’s survival has been nothing short of “a question of touch and go” (he cites the Cuban Missile Crisis in 1963 as an example of how narrowly we escaped extinction).  There are about 22,600 stockpiled nuclear weapons world-wide, 7,770 of which are still operational (Federation of American Scientists). Since there’s no global nuclear non-proliferation treaty, the threat of a nuclear holocaust still exists.  In fact Hawking says, since “the frequency of such occasions [of nuclear warfare] is likely to increase in the future, we shall need great care and judgment to negotiate [all of these incidents] successfully.”

Annalee Newitz, author of “Scatter, Adapt, and Remember: How Humans Will Survive a Mass Extinction” says that “we’re going to have to use all our technological know-how to make dramatic changes to the planet we live on—and then to find ways of escaping it to build cities on the moon and on other planets. Ultimately, our future is among the stars.”

What is the actual situation we’re in?

We’re about to drastically cut our carbon emissions totally against our will, because we’re at peak oil, coal, and natural gas (without which the tarsands can’t be mined in Canada).

According to articles in nature, science, and the International Energy Agency (as well as many other peer-reviewed and government sources), we reached the peak of world oil production in 2005 and have been on a plateau ever since then.

We are at, or near peak coal according to Richard Heinberg and David Fridley in the 18 November 2010 issue of Nature: “The end of cheap coal” which I review at energyskeptic in “Peak Coal is already here or likely by 2020 — if true — IPCC 100 year projections too high?”

We’re also probably at or near peak natural gas due to how expensive it is to drill for it (a financial crash would end the current fracking in the USA), much of it is “stranded” (too far from cities to lay million-dollar-per-mile pipelines), and so on.

Nor are there any alternative solutions to fossil fuels given that we face a liquid fuel crisis since 97% of transportation runs on oil (tractors to plant and harvest crops, trucks to deliver crops, etc). There aren’t enough plants to make biofuels (see energyskeptic “Peak Soil: Why Cellulosic and other Biofuels are Not Sustainable and a Threat to America’s National Security”).

Electrical generation of any kind is not a “fix”. Wind, solar, and other “alternatives” depend on fossil fuels throughout their life cycle. See the energy section of energyskeptic for details.

What are the real “solutions” to our quandary?

At this point it’s time for people to get more realistic about what’s required to cope with the die-off ahead. To offer the false hope of escaping to another planet or harming our planet even more by geoengineering (there are real downsides that aren’t discussed in this book, let alone that these “fixes” aren’t feasible without lots of fossil fuels, which are starting to decline).

It’s probably too late to do anything, but governments could help a great deal by setting one-child per women incentives, and drastically lowering immigration levels so that countries that continue to grow their population and exacerbate the world-wide “Tragedy of the Commons” can’t solve their dilemma by exporting excess people.

Which at this point is a bit like war — the Roman Empire partly fell from excess immigration of the “Barbarians” who were fleeing the Huns, and sought out the much improved standard of living in the Roman Empire. 99% of them were not “invading” — they were immigrating there peacefully to live a better lifestle. Read more about this in The Fall of Rome: And the End of Civilization.

The carrying capacity of the USA without fossil fuels is 100 million people. It is considered racist to even mention lowering the number of immigrants, mainly because right-wing think tanks have made it politically incorrect, since the wealthy are the only ones who benefit from lower labor costs. Well, of course it’s a bit more complicated than that, if you’re interested in learning more, this very important article is free on the internet: Roy Beck and Leon Kolankiewicz. “The Environmental Movement’s Retreat from Advocating U.S. Population Stabilization”. The Journal of Policy History (Penn State University Press); Vol. 12, No. 1 January 1, 2000

———————-

There are more and more books about the true nature of our situation, and in the required happy bit about the “solutions” the author says we can always move to another solar system.  But wait — it’s not so easy.  Aside from all rockets being driven now by fossil fuels, which we won’t have much of in the future, where would we go?

Red Dwarf stars are 75% of the stars in our galaxy, but they’re much smaller and cooler than our sun.

“The habitable zone around low-mass stars is considerably closer to the star than for sun-like stars, due to the lower temperature … Such proximity produces new hazards: susceptibility to stellar activity and coronal mass ejections, tidal forces, stronger magnetic forces, etc.”

So habitable planets would have to be much closer than Earth is to the Sun.

But a planet close enough to sustain life would have such extreme tides that the oceans would evaporate, because “stars with a mass less than a third of that of our sun have habitable zones so close in that this tidal heating would evaporate any planet’s water, the researchers found (arxiv.org/abs/1203.5104)”

Light from the planet’s star would then split the water vapor into hydrogen, which would escape into space, and oxygen, which could go on to form the greenhouse gas carbon dioxide. Planets blanketed in CO2 would heat up further, developing into uninhabitable hothouses like Venus, the team concludes.

Read more about it at:

Rory Barnes. Habitability of planets orbiting cool stars.

6 April 2012. Tides turn some habitable planets hellish. New Scientist.
Tides evoke the sea, but they may dry out what would otherwise be habitable planets around small stars, making them hostile to life.

Rory Barnes of the University of Washington in Seattle and his colleagues calculated what would happen to Earth-like planets orbiting the most common type of star in the galaxy: red dwarfs.

These stars are much cooler and fainter than the sun, meaning the habitable zones around them – in which planets can have liquid water on their surface – are much closer in. Any planets orbiting in those zones feel very strong gravitational tugs from the star.

Unless such a planet travels on a perfectly circular orbit, the strength of the star’s pull varies at different points along its path. This squeezes and stretches the planet, heating it up.

Stars with a mass less than a third of that of our sun have habitable zones so close in that this tidal heating would evaporate any planet’s water, the researchers found (arxiv.org/abs/1203.5104).

Light from the planet’s star would then split the water vapor into hydrogen, which would escape into space, and oxygen, which could go on to form the greenhouse gas carbon dioxide. Planets blanketed in CO2 would heat up further, developing into uninhabitable hothouses like Venus, the team concludes.

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Science book review of Vaclav Smil’s “Approaching the Limits”

Posted on July 14, 2013 by
Steven W. Running  Science 15 March 2013:
Vol. 339 no. 6125 pp. 1276-1277
DOI: 10.1126/science.1235886

Approaching the Limits

Harvesting the Biosphere What We Have Taken from Nature by Vaclav Smil MIT Press, Cambridge, MA, 2012. 315 pp. $29, £19.95. ISBN 9780262018562.

One of the foundational principles of biology is that a population cannot grow forever in a finite ecosystem—a progressive system feedback of starvation, predation, and disease limits uncontrolled growth.

The global human population has now nearly tripled since 1950, and economic activity increased tenfold, leading many to suggest that humanity is heading toward a population and consumption overshoot (resource depletion and correction, as economists would say).

In Harvesting the Biosphere, Vaclav Smil traces the historical development of human consumption of biological resources and evaluates whether we could be approaching important global limits. Smil (an economist at the University of Manitoba) has written several books on global energy and other resource issues; here, he focuses on human consumption of the plant and animal life and whether current trends are sustainable.

One cannot assume that all of global NPP is potentially available for human use. Some regions of the Amazon or Siberia, for example, are too remote for harvest. More important, do we really want to plow and clear the whole world? Most of us want to preserve some natural systems for biodiversity, ecosystem services (such as water and air purification), recreation, or aesthetic beauty. Human settlements and infrastructure, termed impervious surfaces, presently cover only 0.44% of Earth’s continental surface, whereas agriculture and grazing lands cover about 40%. Although global NPP currently appears stable, Smil suggests the great potential for pollution, exhaustion of soil nutrients, and irrigation depletion to substantially reduce the future NPP available for humanity. In addition, bioenergy is emerging as a massive new demand on NPP. Should fossil fuels become scarce, expensive, or unwanted, biofuels could, if allowed by policy and economic strategies, consume all remaining available NPP (2).

The future limits of HANPP become an urgent policy issue when one considers the 40% increase in global population expected over the next three or four decades and the expansion in living standards aspired to by the under-developed world. Smil expects that current policies will lead to a2-3 fold increase in HANPP demand in the next half century, and he rightfully asks if this increase is possible.

Scholars around the world have been asking roughly this same question since 1972, when the landmark Limits to Growth book appeared (3). More recent analyses—such as the global human footprint, planetary boundaries, and Gaia—address the question from various angles. Each has indicated that another half-century of the current trajectory of human development, consumption, and economic aspirations does not appear possible (4–7).

Smil’s final recommendations echo others: global population must be stabilized at or below 9 billion; agriculture has to become sustainable, no longer relying on fossil-fuel–based fertilizers and mining groundwater for irrigation; meat consumption must be moderated; and food storage and processing must be improved and wastage minimized. Crucially, the rich nations have to share global resources more equitably with emerging countries, as simply growing more does not appear possible.

Full of recent references and statistics, Harvesting the Biosphere adds to the growing chorus of warnings about the current trajectory of human activity on a finite planet, of which climate change is only one dimension. One can quibble with some assumptions or tweak Smil’s calculations, but the bottom line will not change, only the time it may take humanity to reach a crisis point.

Systems ecology teaches that the human population and consumption trajectories need a stronger feedback control than currently exists. Either we are smart enough to craft that feedback mechanism ourselves, or the Earth system will ultimately provide it.

Unfortunately, the tragedy of the commons suggests that collective international actions to voluntarily reduce consumption are contrary to human nature.

References

1. P. M. Vitousek, et al. Human Appropriation of the Products of Photosynthesis. Nearly 40% of potential terrestrial net primary productivity is used directly, co-opted, or foregon because of human activities. Bioscience 36, 368 (1986).

2. W. K. Smith et al, Global Bioenergy capacity as constgrained by observed biospheric productivity rates.  Bioscience 62, 911 (2012).

3. D. H. Meadows et al., The Limits to Growth: A Report for the Club of Rome’s Project on the Predicament of Mankind (Universe, New York, 1972).

4. www.footprintnetwork.org.

5. J. Lovelock. The Vanishing Face of Gaia: A Final Warning (Basic, New York, 2010).

6. J. Randers. 2052: A Global Forecast for the Next Forty Years (Chelsea Green, White River Junction, NH, 2012).

7. A. Wijkman, et al. Bankrupting Nature: Denying Our Planetary Boundaries (Routledge, London, ed. 2, 2012)

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China is working on cyber attacks of our infrastructure and stealing secrets

Posted on July 13, 2013 by

Stone, R. March 1, 2013.  A Call to Cyber Arms. Science, Vol. 339 no. 6123 pp. 1026-1027

China’s extensive cyber research activities and allegations over cyber espionage have put the United States on high alert.

XI’AN, CHINA—The leaflet posted in the school of information engineering here at Xi’an Jiaotong University was brief but enticing, offering computer-savvy graduates a hefty stipend and the chance to serve their motherland. “I was curious,” says Liu, who asked that only his surname be used in this article. It was the spring of 2007, and Liu, then 24 years old, was wrapping up a master’s degree in computer algorithms. Encouraged by his supervisor, Liu called the number on the leaflet; that summer, he joined an elite corps of the People’s Liberation Army (PLA) that writes code designed to cripple command-and-control systems of enemy naval vessels.

PLA writings call the electromagnetic spectrum “the fifth domain of battle space,” putting cyberspace on an equal footing with ground, air, sea, and space. Cyber conflicts “threaten national security and the very existence of the state,” two scholars with the Academy of Military Sciences wrote in China Youth Daily in 2011. State media regularly tout PLA activities in cyber defense, a catchall term encompassing everything from surveillance and espionage to weapons such as electromagnetic pulse generators that disable computer networks and malware designed to take down power grids or contaminate water supplies. Augmenting PLA efforts is a legion of civilian researchers and hackers whose efforts ostensibly are directed at repelling electronic intruders. In 2011, more than 8.5 million computers in China “were attacked by rogue programs every day,” a 48% increase over the previous year, says Li Yuxiao, a cyber law expert at Beijing University of Posts and Telecommunications.

But evidence is accumulating that China can dish it out, too. In a report issued last week, the U.S. computer security firm Mandiant tracked one especially adept group of hackers, sometimes called the Comment Crew or Comment Group, to a neighborhood in Shanghai housing Unit 61398, a bureau of the PLA General Staff Department’s Third Department. According to Mandiant, other computer security analysts, and U.S. State Department sources, hackers in China have gathered gigabytes of data on industrial secrets, military hardware, and government strategy for political negotiations.

This is not a unilateral arms buildup. Another heavyweight in the cyber arena is Russia; hackers took down Georgian government servers in advance of Russia’s invasion of that former Soviet republic in August 2008. The United States, too, has gone all-in on cyber warfare. In 2009, it established the U.S. Cyber Command in Fort Meade, Maryland, to conduct “full-spectrum military cyberspace operations.” The Defense Department’s operational needs “will require the integration of cyber and electronic warfare at unprecedented levels,” said Regina Dugan, then-director of the U.S. Defense Advanced Research Projects Agency, in a statement released by DARPA before the Senate took up the 2013 defense authorization. According to U.S. Defense Secretary Leon Panetta, the Pentagon spends about $3 billion a year on cyber security.

Now that Pandora’s box is open, the United States fears that it, too, may someday be on the receiving end of an effective attack. In his State of the Union speech on 12 February, U.S. President Barack Obama declared that unidentified enemies are “seeking the ability to sabotage our power grid, our financial institutions, [and] our air traffic control systems.” That day, he signed an executive order to strengthen cyber defenses and called on Congress to pass legislation that would “give our government a greater capacity to secure our networks and deter attacks.” Last week, the U.S. Department of Energy announced $20 million in funding for the development of technologies to strengthen the cyber security of delivery systems for electricity, oil, and gas.

A one-two punch featuring a cyber attack on critical infrastructure and a physical strike against U.S. targets could leave the country reeling from a “cyber Pearl Harbor,” Panetta warned in a speech last October. “It would paralyze and shock the nation and create a new, profound sense of vulnerability,” he said.

Raising an army

In a conflict in the Pacific, the USS Blue Ridge, the U.S. Navy’s command ship in the region, would be a ripe target for a cyber strike.

At Dalian University of Technology in northeast China, a pair of researchers funded by the science ministry and the National Natural Science Foundation of China published a report in Safety Science in July 2011 on vulnerabilities in the western U.S. power grid.

China so far has shown only some of its cards. Chinese hackers have allegedly used computer network exploitation techniques such as spearphishing, in which malware is embedded in target computers, to harvest data from a long list of Fortune 500 companies, think tanks, and government agencies. Since 2006, the Mandiant report documents, the Shanghai-based hacking group it tracked has pilfered hundreds of terabytes of data from 141 organizations, including 115 in the United States. Information technology and aerospace firms were targeted most frequently. Mandiant said it believes the activity it observed “represents only a small fraction of the cyber espionage” committed by the Shanghai outfit.

Delays and cost overruns in the U.S. F-35 fighter jet program “may be the result of cyber espionage, as could the rapid development of China’s J-20 stealth fighter,” Lewis testified before the U.S. Congress last April. “Cyber espionage is the most pressing threat we face,” he asserted.

Related articles

Electric Grid

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Ground water declining at an alarming rate in Iraq, Iran, Syria, and Turkey

Posted on July 13, 2013 by

[ Lack of water in this region is destabilizing and thus could affect oil production as desperate populations migrate, civil wars, and social unrest unfold.  Alice Friedemann   www.energyskeptic.com  author of “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer]

22 Feb 2013. Drying out the cradle of civilization. Science vol 339 p.889

Figure

New satellite data paint a picture of humans draining the region’s meager water resources at an alarming rate. By measuring subtle changes in the pull of gravity over parts of Turkey, Syria, Iraq, and Iran from 2003 through 2009, NASA’s twin GRACE satellites have revealed a dramatic loss of about 90 cubic kilometers of ground water (reds are largest losses), as reported last week in Water Resources Research. Farmers and other water users struck by a 2007 drought apparently had to withdraw water from wells faster than rain could replenish it.

 

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China food security: climate change likely to reduce rice, wheat, and other crop yields

Posted on July 13, 2013 by

Climate change is also likely to lower wheat production:  Global warming will have a bad effect on heat-sensitive wheat, slashing yields even more than was originally feared.  It could be much harder than we thought to feed everyone in a warmer world. Hot spells are cutting wheat yields in northern India, and models of global warming’s effect on crops may have underestimated the problem by a huge amount…an average warming of 2 °C may [cause losses] 50% greater than thought (Nature Climate Change, DOI: 10.1038/nclimate1356).  Earlier studies suggested that, by 2050, warming could cut wheat yields by 30 per cent in places like India – a figure that may now be optimistic. Yet global yields need to rise 50 per cent by then to feed the world’s growing population (Feb 3, 2012.  Extreme heat ages vital crop. New Scientist.)

Christina Larson.    February 8, 2013. Losing Arable Land, China Faces Stark Choice: Adapt or Go Hungry.  Science (339): 644-645

Warming is expected to trigger more episodes of heat stress that can sterilize the pollen of China’s most important staple grain: rice.

For half a century, Chinese scientists have been flocking to this spot on the eastern rim of the North China Plain, China’s breadbasket, to probe pressing agricultural questions. The region just north of the Yellow River is ground zero for tackling food-security challenges such as flood control, drought, wind erosion, and soil alkalinity. To this list of concerns, researchers have now added climate change and its potential impact on grain yields.

Across the globe, scientists and policy-makers are studying how climate change will affect agriculture. But in China, the question is especially urgent. The country has roughly 20% of the world’s population but only 7% of its arable land—a share that is shrinking in the face of rapid urbanization. From 1998 to 2006, more than 860,000 hectares of arable land were swallowed up by cities each year on average, according to data from China’s Ministry of Land and Resources.

Changing dietary habits, meanwhile, are fueling a rapid rise in food consumption. Accompanying the expansion of China’s middle class is a growing appetite for meat, which heaps more pressure on land and water resources. In 1978, China’s total meat consumption was 8 million tons, but by 2012 it had ballooned to 71 million tons, according to the Earth Policy Institute, a think tank in Washington, D.C. In 2011, one-third of China’s total grain harvest was converted to feed for livestock and aquaculture.

Climate change could exacerbate the fallout. According to the Chinese government’s Second National Assessment Report on Climate Change in 2011, rising sea levels are likely to threaten China’s eastern rice-growing regions by 2050, about the time that eight provinces in the north expect to face severe water shortages.

Already, annual mean temperatures near Yucheng rose 0.8°C between 1955 and 2011, according to China Meteorological Administration (CMA) records. The uptick is felt most in winter and spring—coinciding with the growing season for winter wheat, the region’s most important staple crop.

Contrary to conventional wisdom, rising temperatures in China’s heartland are translating into shorter overall growing periods. Although warming accelerates the early stages of wheat growth, the length of the reproductive period—the phase spanning flowering and maturity—remains roughly the same for cultivars now commonly grown in the region. Faster growth may mean fewer grains, spelling lower yields.

By comparing records compiled by CMA and provincial agricultural departments between 1980 and 2008, Tao has attempted to tease out the climate signal from other factors affecting yield, such as crop management and fertilizer use. In a paper published online last October in Climate Research, Tao linked changes across China in temperature, precipitation, and solar radiation over those 3 decades with 1.3% and 1.7% reductions in projected wheat and maize yields, respectively. That translates to hundreds of thousands of tons of lost harvest. A team at the Chinese Academy of Agricultural Sciences in Beijing and the International Food Policy Research Institute in Washington, D.C., has also identified a significant impact from climate change. They reported in Agricultural and Forest Meteorology in 2009 that warming caused a 4.5% decline in growth of wheat yields across China from 1979 to 2000.

Regional variation complicates the picture. In frigid northern China, where annual mean temperatures have risen faster than the national average, warming has extended arable land northward. But the potential agricultural benefits may be hard to reap, Tao warns, as climate change is expected to increase the frequency of drought and extreme weather events in an already water-stressed region.

Much of northern China is dry, making agriculture dependent upon irrigation from the Yellow River and the northern China aquifer. But pollution has degraded the quality of China’s “Mother River” and growing cities are siphoning off water for urban uses. Some 120 billion cubic meters more water were pumped from the aquifer than were replaced by rainfall over the last 4 decades, resulting in a steadily retreating water table (Science, 18 June 2010, p. 1462).

Rapid plant maturation and water shortages are threatening wheat in the north; heat stress and rising sea levels are the big worries in rice-growing areas in the south and east.

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Soot warming earth even more than thought

Posted on July 13, 2013 by
Richard A. Kerr Science 25 January 2013: Vol. 339 no. 6118 p. 382 DOI: 10.1126/science.339.6118.382

Soot Is Warming the World Even More Than Thought

A new study finds that soot is warming the climate about twice as fast as scientists had estimated.

With roughly 8 million tons of soot produced each year by burning everything from coal in power plants to oil in ship’s boilers, that’s bad news for the planet.

Scientists began the 232-page study—published last week in the Journal of Geophysical Research: Atmospheres—4 years ago in response to calls for drastic reductions in emissions of soot, called black carbon in the scientific literature. Soot particles roughly 100 nanometers in diameter were obviously absorbing solar energy and passing it on to the atmosphere, adding to the warming caused by greenhouse gases.

Under the auspices of the International Global Atmospheric Chemistry Project, 31 researchers from nine countries in a range of disciplines came together to assess the climate effects of soot. Working from published field observations, the authors looked at all the effects of soot on the planet’s retention of solar energy as well as the effects of other products of soot-producing combustion. They then tried to understand why different researchers got different answers from their climate models. “It’s a deeper view,” Bond says.

The new, deeper view—which drew 600 comments from 20 peer reviewers—finds a prominent role for soot in global warming.

All the ways soot can affect climate—among them by:

  • absorbing sunlight
  • shrinking cloud droplets and thus brightening clouds
  • darkening ice and snow

This adds 1.1 watts per square meter (W/m2) to the climate system, the study concludes.

“That’s a big number,” Bond says. It puts soot second behind carbon dioxide, which accounts for 1.66 W/m2.

Soot’s contribution to the warming is roughly twice as large as estimated in the 2007 assessment made by the Intergovernmental Panel on Climate Change.

 

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Climate Change deadlines: the longer we do nothing, the worse it gets

Posted on July 13, 2013 by

Thomas F. Stocker Science 18 January 2013:
Vol. 339 no. 6117 pp. 280-282
DOI: 10.1126/science.1232468

The Closing Door of Climate Targets

Robust evidence from a range of climate–carbon cycle models shows that the maximum warming relative to pre-industrial times caused by the emissions of carbon dioxide is nearly proportional to the total amount of emitted anthropogenic carbon. This proportionality is a reasonable approximation for simulations covering many emissions scenarios for the time frame 1750 to 2500. This linear relationship is remarkable given the different complexities of the models and the wide range of emissions scenarios considered. It has direct implications for the possibility of achieving internationally agreed climate targets.

The considerations presented here are based on the assumption of a generic set of carbon dioxide emissions scenarios that reasonably approximate what is presently observed and what needs to be done to limit warming below a specific global mean temperature increase. In these idealized and illustrative emissions scenarios, emissions follow an exponential increase with a constant rate until a given year, after which the emissions decrease exponentially at a constant rate. The scenarios delineate the boundaries for any discussion and decision process for global measures limiting anthropogenic climate change.

Figure

For example, under these assumptions, keeping CO2-induced global warming below 2°C would require emissions reductions of almost 3.2% per year from 2020 onward; this is more than doubled if Global mitigation doesn’t begin until 2032. So every year counts; the longer the delay, the more reductions are required later.

Without mitigation of carbon dioxide, it becomes impossible to reach lower temperatures, the climate target closes irreversibly.

Under the present illustrative assumptions, the 1.5°C target expires after 2028, and the 2°C target vanishes after 2044. These times would be later if a period of stabilized emissions preceded the Global Mitigation Strategy (GMS). The more likely situation, however, is that a specific climate target becomes unreachable much earlier, because there are upper limits on sustained emissions reduction rates imposed by what the countries’ economies can realize collectively given the present state of technology and infrastructure.

Economic models estimate that feasible maximum rates of emissions reduction may not exceed about 5% per year (5). Under this assumption, the 1.5°C target has become unachievable before 2012, the 2°C target will become unachievable after 2027, and the 2.5°C target will become unreachable after 2040.

These years are only illustrative of the finite time that climate targets remain available options in the presence of continued greenhouse gas emissions.

As the emissions scenarios considered here illustrate, even well-intentioned and effective international efforts to limit climate change must face the hard physical reality of certain temperature targets that can no longer be achieved if too much carbon has already been emitted to the atmosphere. Both delay and insufficient mitigation efforts close the door on limiting global mean warming permanently. This constitutes more than a climate change commitment: It is the fast and irreversible shrinking, and eventual disappearance, of the mitigation options with every year of increasing greenhouse gas emissions.

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Climate change is causing increased salinity in water and soil world-wide

Posted on July 13, 2013 by

November 23, 2012. Climate Change–Induced Salinity Threatens Health.  Science Vol 338: 1028-1029

Sea-level rise, storm surges, and cyclones exacerbated by climate change have begun to severely affect coasts and river estuaries in low-income countries. The resulting increased salinity in soil and drinking water has health implications for large populations.

In coastal Bangladesh, natural drinking water sources such as rivers and groundwater are threatened by saltwater intrusion from the Bay of Bengal.

The increased salinity in drinking water will likely affect health over the long term [because it increases blood pressure], potentially leading to a substantial rise in cases of hypertension, as well as other associated health problems.

Salinity is also affecting other areas such as the Pearl River Delta, China (5); the San Joaquin Delta, California (6); and in the Netherlands (7), Australia (8), and Brazil (9). These estimates show that salinity may be an increasing problem in a number of coastal areas affected by intrusion of salty water into rivers.

To mitigate the risk of high blood pressure, cardiovascular disease, and other associated health problems caused by climate change–induced salt intrusions, we must take immediate action. Adaptation measures, including rainwater harvesting and solar distillation, require coordination among governments and nongovernmental organizations. Putting these prevention plans in place will be far less expensive than treating the disease that will occur later if salt intrusions continue unabated.

 

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Gonorrhea could soon be untreatable according to World Health Organization

Posted on July 13, 2013 by

Science 15 June 2012: Vol. 336 no. 6087 pp. 1364-1365

WHO Warns of Drug-Resistant Gonorrhea

The World Health Organization (WHO) warned that gonorrhea, which infects 106 million people in the world each year, could soon become untreatable.

In its Global action plan to control the spread and impact of antimicrobial resistance in Neisseria gonorrhoea, released on 6 June, the public health arm of the United Nations sounds a dire note. “The loss of effective and readily available treatment options will lead to significant increases in morbidity and mortality,” the authors write.

Gonorrhea, if left untreated, can lead to infertility in men and women and increases the risk of contracting and transmitting HIV. It can also cause blindness in children born to infected women. The gonorrhea pathogen is now resistant to many common antibiotics such as penicillin and tetracyclines; only one class of antibiotics, called cephalosporins, has remained effective. But in the last few years, Australia, Sweden, Japan, the United Kingdom, and other countries have reported cases of resistance to cephalosporins.

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