Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Category Archive: Climate Change

  1. Urban floods intensifying, countryside drying up

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    • An exhaustive global analysis of rainfall and rivers shows signs of a radical shift in streamflow patterns, with more intense flooding in cities and smaller catchments coupled with a drier countryside

    August 14, 2017 University of New South Wales  read full ScienceDaily article here

    Drier soils and reduced water flow in rural areas — but more intense rainfall that overwhelms infrastructure and causes flooding and stormwater overflow in urban centers. That’s the finding of an exhaustive study of the world’s river systems, based on data collected from more than 43,000 rainfall stations and 5,300 river monitoring sites across 160 countries…

    …”The [study] relied on observed flow and rainfall data from across the world, instead of uncertain model simulations, means we are seeing a real-world effect — one that was not at all apparent before.”

    “It’s a double whammy,” said Conrad Wasko, lead author of the paper and postdoctoral fellow at UNSW’s Water Research Centre. “People are increasingly migrating to cities, where flooding is getting worse. At the same time, we need adequate flows in rural areas to sustain the agriculture to supply these burgeoning urban populations.”

    …[the study] found warmer temperatures lead to more intense storms, which makes sense: a warming atmosphere means warmer air, and warmer air can store more moisture…But…why is flooding not increasing at the same rate as the higher rainfall?

    The answer turned out to be the other facet of rising temperatures: more evaporation from moist soils is causing them to become drier before any new rain occurs — moist soils that are needed in rural areas to sustain vegetation and livestock. Meanwhile, small catchments and urban areas, where there are limited expanses of soil to capture and retain moisture, the same intense downpours become equally intense floods, overwhelming stormwater infrastructure and disrupting life.

    Global flood damage cost more than US$50 billion in 2013; this is expected to more than double in the next 20 years as extreme storms and rainfall intensify and growing numbers of people move into urban centres. Meanwhile, global population over the next 20 years is forecast to rise another 23% from today’s 7.3 billion to 9 billion — requiring added productivity and hence greater water security….

    “We need to adapt to this emerging reality,” said Sharma. “We may need to do what was done to make previously uninhabitable places liveable: engineer catchments to ensure stable and controlled access to water. Places such as California, or much of the Netherlands, thrive due to extensive civil engineering. Perhaps a similar effort is needed to deal with the consequences of a changing climate as we enter an era where water availability is not as reliable as before.”…

    Conrad Wasko, Ashish Sharma. Global assessment of flood and storm extremes with increased temperatures. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-08481-1

     

     

  2. Ozone treaty taking significant bite out of US greenhouse gas emissions

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    • Reducing ozone-depleting substances from 2008 to 2014 eliminated the equivalent of 170 million tons of carbon dioxide emissions each year– equivalent of 50% of US CO2 and other GHG over same period.
    August 14, 2017 American Geophysical Union see full ScienceDaily article here
    The Montreal Protocol, the international treaty adopted to restore Earth’s protective ozone layer in 1989, has significantly reduced emissions of ozone-depleting chemicals from the United States. In a twist, a new study shows the 30-year old treaty has had a major side benefit of reducing climate-altering greenhouse gas emissions from the US.
    That’s because the ozone-depleting substances controlled by the treaty are also potent greenhouse gases, with heat-trapping abilities up to 10,000 times greater than carbon dioxide over 100 years.The new study is the first to quantify the impact of the Montreal Protocol on U.S. greenhouse gas emissions with atmospheric observations.

    .Hu added that the benefits of the Montreal Protocol on greenhouse gas emissions would likely grow in the future. By 2025, she projects that the effect of the Montreal Protocol will be to reduce U.S. greenhouse gas emissions by the equivalent of 500 million tons of carbon dioxide per year compared with 2005 levels. This reduction would be equivalent to about 10 percent of the current U.S. emissions of carbon dioxide.

    Lei Hu et al. Considerable contribution of the Montreal Protocol to declining greenhouse gas emissions from the United States. Geophysical Research Letters, 2017; DOI: 10.1002/2017GL074388

  3. Human-caused warming likely led to recent streak of record-breaking temperatures globally

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    • It is “extremely unlikely” 2014, 2015 and 2016 would have been the warmest consecutive years on record without the influence of human-caused climate change, according to the authors of a new study.

    August 10, 2017 American Geophysical Union  Read full ScienceDaily article here

    ….Temperature records were first broken in 2014, when that year became the hottest year since global temperature records began in 1880. These temperatures were then surpassed in 2015 and 2016, making last year the hottest year ever recorded. In 2016, the average global temperature across land and ocean surface areas was 0.94 degrees Celsius (1.69 degrees Fahrenheit) above the 20th century average of 13.9 degrees Celsius (57.0 degrees Fahrenheit), according to NOAA.

    Combining historical temperature data and state-of-the-art climate model simulations, the new study finds the likelihood of experiencing consecutive record-breaking global temperatures from 2014 to 2016 without the effects of human-caused climate change is no greater than 0.03 percent and the likelihood of three consecutive record-breaking years happening any time since 2000 is no more than 0.7 percent.

    When anthropogenic warming is considered, the likelihood of three consecutive record-breaking years happening any time since 2000 rises to as high as 50 percent, according to the new study…

    Michael E. Mann, Sonya K. Miller, Stefan Rahmstorf, Byron A. Steinman, Martin Tingley. Record Temperature Streak Bears Anthropogenic Fingerprint. Geophysical Research Letters, 2017; DOI: 10.1002/2017GL074056

  4. Warming + humidity may mean biannual heatwaves >40°C [104°F] ; Super-heatwaves of 55°C [131°F] to emerge if global warming continues

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    • Heatwaves amplified by high humidity can reach above 40°C and may occur as often as every two years, leading to serious risks for human health.
    • If global temperatures rise with 4°C, a new super heatwave of 55°C can hit regularly many parts of the world, including Europe, warn researchers.

    09 Aug 2017 04:38 AM PDT  Read full ScienceDaily article here

    the combinations of [high heat and humidity will] leave ever more people exposed to significant health risks, especially in East Asia and America’s East Coast.

    Warm air combined with high humidity can be very dangerous as it prevents the human body from cooling down through sweating, leading to hyperthermia. As a result, if global warming trends continue, many more people are expected to suffer sun strokes, especially in densely populated areas of India, China and the US….

    …the effect of relative humidity on heatwaves’ magnitude and peak might be underestimated in current research. The results of the study support the need for urgent mitigation and adaptation action to address the impacts of heatwaves, and indicate regions where new adaptation measures might be necessary to cope with heat stress.

    Simone Russo, Jana Sillmann, Andreas Sterl. Humid heat waves at different warming levels. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-07536-7

  5. Government Report Finds Drastic Impact of Climate Change on U.S.; See Report Executive Summary at NY Times

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    • A draft report by scientists from 13 federal agencies, which has not yet been made public but was obtained by The New York Times, concludes that Americans are feeling the effects of climate change right now.
    • Evidence for a changing climate abounds, from the top of the atmosphere to the depths of the oceans
    • Scientists fear Administration will dismiss or suppress the most comprehensive climate report
    • The report was completed this year and is part of the National Climate Assessment, which is congressionally mandated every four years.

    Lisa Friedman Aug 7 2017 Read full NY Times articles here

    Read the Draft of the Climate Change Report here (see Executive Summary starting page 12)

    WASHINGTON — The average temperature in the United States has risen rapidly and drastically since 1980, and recent decades have been the warmest of the past 1,500 years, according to a sweeping federal climate change report awaiting approval by the Trump administration.

    The draft report by scientists from 13 federal agencies, which has not yet been made public, concludes that Americans are feeling the effects of climate change right now. It directly contradicts claims by President Trump and members of his cabinet who say that the human contribution to climate change is uncertain, and that the ability to predict the effects is limited.

    Evidence for a changing climate abounds, from the top of the atmosphere to the depths of the oceans,” a draft of the report states. A copy of it was obtained by The New York Times.

    The authors note that thousands of studies, conducted by tens of thousands of scientists, have documented climate changes on land and in the air. “Many lines of evidence demonstrate that human activities, especially emissions of greenhouse (heat-trapping) gases, are primarily responsible for recent observed climate change,” they wrote.

    The report was completed this year and is a special science section of the National Climate Assessment, which is congressionally mandated every four years. The National Academy of Sciences has signed off on the draft report, and the authors are awaiting permission from the Trump administration to release it.

    One government scientist who worked on the report, Katharine Hayhoe, a professor of political science at Texas Tech University, called the conclusions among “the most comprehensive climate science reports” to be published. Another scientist involved in the process, who spoke to The New York Times on the condition of anonymity, said he and others were concerned that it would be suppressed….

  6. U.S. had 2nd warmest year through July 2017

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    • Northern Plains drought intensified, wildfires raged in the West, and rains flooded parts of the Midwest and Northeast.

    August 8, 2017  see full NOAA monthly update here

    This monthly summary from NOAA’s National Centers for Environmental Information is part of the suite of climate information services NOAA provides to government, business, academia and the public to support informed decision-making.

    The July average temperature for the contiguous U.S. was 75.7°F, 2.1°F above the 20th century average and was the 10th warmest July in 123 years of record-keeping. Much-above-average temperatures were observed across the West and parts of the Mid-Atlantic and Southeast. The year-to-date (January-July) average temperature for the contiguous U.S. was 54.5°F, 3.2°F above average and second warmest on record. This was slightly warmer than the same period in 2006 and 1.2°F cooler than the record set in 2012.

    …Above-average temperature spanned the nation for the first seven months of 2017 with only parts of the Northwest cooler than average. Much-above-average temperatures were observed for most locations in the Southwest and from the Rockies to the East Coast, mostly due to record and near-record warmth early in the year. Florida, North Carolina and South Carolina had their warmest January-July on record.

    …According to the August 1 U.S. Drought Monitor report, 11.8 percent of the contiguous U.S. was in drought, up about 3.7 percent compared to the end of June. Drought improved across parts of the Southwest, southern High Plains and in the Washington, DC, area. Drought intensified and expanded in the Northwest, Northern Rockies and Central to Northern Plains driven by below-average precipitation and above-average temperatures. The drought and heat decimated crops in the Northern Plains. Drought and abnormally dry conditions developed in parts of the Southeast and northern Maine. Drought continued to impact parts of Hawaii and western Alaska….

  7. Climate change to cause humid heatwaves that will kill even healthy people

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    • If warming is not tackled, levels of humid heat that can kill within hours will affect millions across south Asia within decades, analysis finds
    • The analysis also showed that the dangerous 31C WBT level would be passed once every two years for 30% of the population – more than 500 million people – if climate change is unchecked, but for only 2% of the population if the Paris goals are met.

    Extreme heatwaves that kill even healthy people within hours will strike parts of the Indian subcontinent unless global carbon emissions are cut sharply and soon, according to new research.

    Even outside of these hotspots, three-quarters of the 1.7bn population – particularly those farming in the Ganges and Indus valleys – will be exposed to a level of humid heat classed as posing “extreme danger” towards the end of the century.

    The new analysis assesses the impact of climate change on the deadly combination of heat and humidity, measured as the “wet bulb” temperature (WBT). Once this reaches 35C, the human body cannot cool itself by sweating and even fit people sitting in the shade will die within six hours. The revelations show the most severe impacts of global warming may strike those nations, such as India, whose carbon emissions are still rising as they lift millions of people out of poverty….

    The limit of survivability, at 35C WBT, was almost reached in Bandar Mahshahr in Iran in July 2015, where 46C heat combined with 50% humidity. “This suggests the threshold may be breached sooner than projected,” said the researchers. 

    The report demonstrates the urgency of measures to both cut emissions and help people cope better with such heatwaves, he said. There are uncertainties in the modelling – which Schär noted could underestimate or overestimate the impacts – as representing monsoon climates can be difficult and historical data is relatively scarce.

    Prof Chris Huntingford, at the UK Centre for Ecology and Hydrology, said: “If given just one word to describe climate change, then ‘unfairness’ would be a good candidate. Raised levels of carbon dioxide in the atmosphere are expected to cause deadly heatwaves for much of South Asia. Yet many of those living there will have contributed little to climate change.

    Eun-Soon Im, Jermey S. Pal and Elfatih A.B. Eltahir. Deadly heat waves projected in the densely populated agricultural regions of South Asia. Science Advances 02 Aug 2017: Vol. 3, no. 8, e1603322 DOI: 10.1126/sciadv.1603322

  8. Major changes in farming practices needed to offset nutrient loss from increased winter rainfall due to climate change

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    • Main factor driving increased future phosphorus losses was the projected increase in winter rainfall
    • Too many nutrients cause algal blooms in rivers and lakes, suffocating fish and other organisms
    • Dramatic changes needed in farming practices to offset increases in nutrient losses to keep pace with climate change

    August 3, 2017 see full ScienceDaily article here

    To combat repeated, damaging storm events, which strip agricultural land of soil and nutrients, farmers are already adopting measures to conserve these assets where they are needed.

    But in a new paper in the journal Nature Communications, researchers investigating nutrients in runoff from agricultural land warn that phosphorus losses will increase, due to climate change, unless this is mitigated by making major changes to agricultural practices….include a more judicious use of fertilizer including strategies to use soil phosphorus more efficiently, or physical measures to reduce the losses of nutrients from fields.

    …”This paper should alert policy makers and government to the help and support that farmers will need to achieve the scale of agricultural change that may be necessary to keep up with the increase in pollution due to climate change.”

    Nutrients, such as phosphorus and nitrogen are essential to crop and animal growth, but too many nutrients cause algal blooms in rivers and lakes. These suffocate fish and other organisms and require costly remediation by water supply companies. Fertilisers and manures washed off in storms are a major source of nutrients, with more than 60 per cent of the nitrogen and 25 per cent of the phosphorus in our rivers coming from agriculture

    … Our study therefore showed that the main factor driving increased future phosphorus losses was the projected increase in winter rainfall

    M. C. Ockenden, M. J. Hollaway, K. J. Beven, et al. Major agricultural changes required to mitigate phosphorus losses under climate change. Nature Communications, 2017; 8 (1) DOI: 10.1038/s41467-017-00232-0

  9. Less than 2 °C warming by 2100 unlikely

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    • There’s a 5% chance Earth will warm 2 degrees or less by the end of this century
    • There’s a 90% chance that temperatures will increase from 2.0 to 4.9°C if historical trends continue unabated.

    With each passing year, the odds get worse that climate change mitigation efforts will be able to stave off catastrophic warming of more than 2 degrees Celsius, or 3.6 degrees Fahrenheit.

    A new study published on July 31 in Nature Climate Change is the opposite of reassuring when it comes to this math. Using statistical tools, the authors found that there’s a 5% chance Earth will warm 2 degrees or less by the end of this century and a 90% chance that temperatures will increase from 2.0 to 4.9°C if historical trends continue unabated. The other 5%, well that’s worst-case scenario runaway global warming—the kind of thing that keeps geoengineers up at night.

    As for the ambitious 1.5°C target included in the Paris Agreement, there’s apparently only a 1% chance of meeting that (not so surprising considering the planet has already warmed 1°C since pre-industrial times). So as climate change deniers like President Trump, EPA chief Scott Pruitt, and many GOP lawmakers put their money on taking little to no action and somehow escaping devastating warming, in truth it will take a herculean global effort to avoid costly and harmful impacts.

    The reality of human-caused climate change is increasingly clear for anyone to see. Last year was the hottest year on record, and the 12 warmed years on record have all occurred since 1998. 2017 is on track to be the second-warmest year on record; and this even in the absence of an El Niño warming event like 2016’s. According to NASA, the first six months of this year were 0.94°C above the 1950–1980 average…

    …Adrian Raftery, a UW professor of statistics and sociology and lead author on the new study, said while their analysis is compatible with previous estimates, it shows “we’re closer to the margin than we think….The goal of 2 degrees is very much a best-case scenario,” said Raftery in a statement. “It is achievable, but only with major, sustained effort on all fronts over the next 80 years.”

    …Richard Startz, an economist at the University of California at Santa Barbara who worked on the study, told Project Earth the most surprising finding was that population growth will not be a major factor in increased CO2 emissions over the course of the century. This is in large part because most of that growth will occur in Africa, where per capita emissions will remain relatively low.

    What matters a lot more for future warming is actually carbon intensity. According to the study, even though carbon intensity has dropped in recent decades as countries increase energy efficiency and enact carbon-reducing policies, it will need to drop much more to see the kind of progress the global climate community is aiming for with the Paris Agreement targets.

    “Our study already assumes that the trends in carbon intensity will continue to improve,” said Startz. “So more reductions in carbon intensity aren’t enough. We need much faster reductions in carbon intensity than we’ve already been seeing.”

    Startz said in his opinion there are two primary ways to accomplish this: Financial incentives to reduce carbon emissions—like carbon taxes or cap-and-trade programs—and a lot more support for scientific research that would help reduce emissions. “For example, the invention of practical LED lighting has been a small but significant achievement in reducing energy needs,” he said. “If someone could greatly increase battery cost-effectiveness, that would buy us a lot.”

    Adrian E. Raftery, Alec Zimmer, Dargan M. W. Frierson, Richard Startz & Peiran Liu. Less than 2°C warming by 2100 unlikely. Nature Climate Changedoi:10.1038/nclimate3352

  10. Underground magma triggered Earth’s worst mass extinction with greenhouse gases; similar to today’s symptoms

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    • it was principally greenhouse gas emissions triggered by magma intrusions that caused the extinction through abrupt global warming and ocean acidification
    • The more science learns of these past greenhouse gas-driven events, the more uncomfortable the parallels to today become.
    • Geologically fast build-up of greenhouse gas linked to warming, rising sea-levels, widespread oxygen-starved ocean dead zones and ocean acidification are fairly consistent across the mass extinction events, and those same symptoms are happening today as a result of human-driven climate change.

    1 August 2017 by Howard Lee Read full GuardianUK article here

    ….Of some 18 major and minor mass extinctions since the dawn of complex life, most happened at the same time as a rare, epic volcanic phenomenon called a Large Igneous Province (LIP)Many of those extinctions were also accompanied by abrupt climate warming, expansion of ocean dead zones and acidification, like today.

    Earth’s most severe mass extinction, the “Great Dying,” began 251.94 million years ago at the end of the Permian period, with the loss of more than 90% of marine species…. why was the mass extinction event much shorter than the eruptions? And why did the extinction happen some 300,000 years after the lava began to flow?

    In a new study published in Nature Communications, Seth Burgess of the US Geological Survey, along with James Muirhead of Syracuse University and Samuel Bowring of MIT, think they have the answer.

    ….In other words, it wasn’t the lava, it was the underground magma that started the killing, by releasing greenhouse gases.

    Norwegian scientist Henrik Svensen had earlier identified hundreds of unusual volcanic vents called “diatreme pipes” all over Siberia that connected underground intrusions of magma (“sills”) to the atmosphere, showing signs of violent gas explosions. This new work emphasizes the importance of Svensen’s 2009 conclusions:

    The diatremes that have been mapped are the geologic representation of that gas escape on a catastrophic level. Our hypothesis is that the first sills to be intruded are the ones that really do the killing [by] large scale gas escape likely via these diatremes.

    Svensen, who was not involved in Burgess’ study, commented:

    The Burgess et al paper is a crucial step towards a new understanding of the role of volcanism in driving extinctions. It’s not the spectacular volcanic eruptions that we should pay attention too – it’s their quiet relative, the sub-volcanic network of intrusions, that did the job. The new study shows convincingly that we are on the right track.

    Greenhouse gas as a killer

    While other scientists have proposed that an array of killers may have been involved in the end-Permian mass extinction, from mercury poisoning to ultraviolet rays and ozone collapse to acid rain, Burgess argues that it was principally greenhouse gas emissions triggered by magma intrusions that caused the extinction through abrupt global warming and ocean acidification.

    Geologically fast build-up of greenhouse gas linked to warming, rising sea-levels, widespread oxygen-starved ocean dead zones and ocean acidification are fairly consistent across the mass extinction events, and those same symptoms are happening today as a result of human-driven climate change. Even though the duration of those past events was longer, and the volume of emissions was larger than we will produce, we are emitting greenhouse gases around 10 times faster than the most recent, mildest example – the PETM. The rapidity of today’s emissions prompted scientists Richard Zeebe and James Zachos to observe in a 2013 paper:

    The Anthropocene will more likely resemble the end-Permian and end-Cretaceous disasters, rather than the PETM.

    When the promises made for the 2016 Paris Agreement on climate change are added up, they aim to limit peak warming this century to about 3.3ºC compared to about 4.2ºC for the business-as-usual scenario, and the 2ºC limit the world is aiming to stay under. It’s sobering to compare those numbers to the majority of mass extinctions in the geological record which were characterized by abrupt warmings typically around 6-7ºC.

    S. D. Burgess, J. D. Muirhead & S. A. Bowring. Initial pulse of Siberian Traps sills as the trigger of the end-Permian mass extinction. Nature Communications 8, Article number: 164 (2017) doi:10.1038/s41467-017-00083-9