Ecology, Climate Change and Related News

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Tag Archive: warming

  1. Deforestation likely accelerates global warming more than previously thought due to loss of reactive gases cooling effect

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    • Deforestation leads to higher temperatures than previously anticipated as less of the reactive gases that have an overall cooling effect on our climate are created.

    January 11, 2018 University of Leeds

    Deforestation is likely to warm the climate even more than originally thought, scientists warn. Research has found reactive gases emitted by trees and vegetation have an overall cooling effect on our climate, meaning deforestation would lead to higher temperatures than previously anticipated as less of the gases would be created.

    An international team of scientists, led by the University of Leeds, studied the way that reactive gases emitted by trees and vegetation affect the climate.

    Their research, published today in Nature Communications, found these reactive gases cool our climate, meaning deforestation would lead to higher temperatures than previously anticipated as less of the gases would be created.

    ….”We found that the cooling impacts of these gases outweigh the warming impacts, meaning that reactive gases given out by forests have an overall cooling effect on our climate.”

    Dr Scott added, “The warming and cooling effects of these gases are most closely balanced in the tropics, which is where most deforestation is occurring — suggesting that we really need to understand more about the strength of these impacts”

    C. E. Scott, et al. Impact on short-lived climate forcers increases projected warming due to deforestation. Nature Communications, 2018; 9 (1) DOI: 10.1038/s41467-017-02412-4

  2. Climate change drives collapse in marine food webs

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    • Increased ocean temperatures reduce the vital flow of energy from the primary food producers at the bottom (e.g. algae), to intermediate consumers (herbivores), to predators at the top of marine food webs.

    January 9, 2018 University of Adelaide read full ScienceDaily article here

    A new study has found that levels of commercial fish stocks could be harmed as rising sea temperatures… drive the collapse of marine “food webs.” [The research shows] that increased temperatures reduce the vital flow of energy from the primary food producers at the bottom (e.g. algae), to intermediate consumers (herbivores), to predators at the top of marine food webs.

    Such disturbances in energy transfer can potentially lead to a decrease in food availability for top predators, which in turn, can lead to negative impacts for many marine species within these food webs.

    “Healthy food webs are important for maintenance of species diversity and provide a source of income and food for millions of people worldwide…

    …”Whilst climate change increased the productivity of plants, this was mainly due to an expansion of cyanobacteria (small blue-green algae),” said Mr Ullah. “This increased primary productivity does not support food webs, however, because these cyanobacteria are largely unpalatable and they are not consumed by herbivores.”

    ….Most research on ocean warming involves simplified, short-term experiments based on only one or a few species. “If we are to adequately forecast the impacts of climate change on ocean food webs and fisheries productivity, we need more complex and realistic approaches, that provide more reliable data for sophisticated food web models,” said project leader Professor Nagelkerken.

    Hadayet Ullah, Ivan Nagelkerken, Silvan U. Goldenberg, Damien A. Fordham. Climate change could drive marine food web collapse through altered trophic flows and cyanobacterial proliferation. PLOS Biology, 2018; 16 (1): e2003446 DOI: 10.1371/journal.pbio.2003446

  3. Warming ocean water is turning 99 percent of northern Great Barrier Reef sea turtles female; population viability threatened

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    • Rising temperatures are skewing population ratios toward extreme imbalance
    • Green sea turtle embryos develop as male or female depending on the temperature at which they incubate in sand
    • In the cooler southern Great Barrier Reef, 67 percent of hatched juveniles were female. But more than 99 percent of young turtles hatched in sand soaked by warmer waters in the northern Great Barrier Reef were female — with one male for every 116 females.
    By Laurel Hamers January 8, 2018  Read full ScienceNews article here

    Warming waters are turning some sea turtle populations female — to the extreme. More than 99 percent of young green turtles born on beaches along the northern Great Barrier Reef are female, researchers report January 8 in Current Biology. If that imbalance in sex continues, the overall population could shrink.

    Green sea turtle embryos develop as male or female depending on the temperature at which they incubate in sand. Scientists have known that warming ocean waters are skewing sea turtle populations toward having more females, but quantifying the imbalance has been hard.

    The sex ratio in the overall population is “nothing out of the ordinary,” with roughly one juvenile male for every four juvenile females, says study coauthor Michael Jensen, a marine biologist with the National Oceanic and Atmospheric Administration in La Jolla, Calif.

    But breaking the data down by the turtles’ region of origin revealed worrisome results. In the cooler southern Great Barrier Reef, 67 percent of hatched juveniles were female. But more than 99 percent of young turtles hatched in sand soaked by warmer waters in the northern Great Barrier Reef were female — with one male for every 116 females. That imbalance has increased over time: 86 percent of the adults born in the area more than 20 years ago were female….

    Michael Jensen, et al. Environmental Warming and Feminization of One of the Largest Sea Turtle Populations in the World.  Current Biology. Volume 28, Issue 1, p154–159.e4, 8 January 2018 DOI: http://dx.doi.org/10.1016/j.cub.2017.11.057/

    “Combining our results with temperature data show that the northern GBR green turtle rookeries have been producing primarily females for more than two decades and that the complete feminization of this population is possible in the near future.”

  4. 2017 was 3rd warmest year on record for U.S.; 10 hottest US years graphic

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    • Nation experienced 16 weather and climate disasters with total losses of over $300 billion, the costliest on record

    January 8 2018  NOAA’s National Centers for Environmental Information

    Based on preliminary analysis, the average annual temperature for the contiguous U.S. was 54.6°F, 2.6°F above the 20th century average. This was the third warmest year since record keeping began in 1895, behind 2012 (55.3°F) and 2016 (54.9°F), and the 21st consecutive warmer-than-average year for the U.S. (1997 through 2017). The five warmest years on record for the contiguous U.S. have all occurred since 2006.

     

    The 10 Hottest U.S. Years on Record

    Graphic from Climate Central- 10 hottest US years

    During the year, the U.S. experienced 16 weather and climate disasters with losses exceeding $1 billion, with total costs of approximately $306 billion – a new U.S. annual record. The previous costliest year for the U.S. was 2005 with losses of $215 billion driven in large part by Hurricanes Katrina, Wilma and Rita. The number of events (16) ties 2011 for most billion-dollar disasters in a single year.

    Some of the more noteworthy events included the western wildfire season, with total costs of $18 billion, tripling the previous U.S. annual wildfire cost record. Hurricane Harvey had total costs of $125 billion, second only to Hurricane Katrina in the 38-year period of record for billion-dollar disasters. Hurricanes Maria and Irma had total costs of $90 billion and $50 billion, respectively. Hurricane Maria now ranks as the third costliest weather and climate disaster on record for the nation and Irma ranks as the fifth costliest.

    Other Notable Extremes

    The U.S. Climate Extremes Index (USCEI)  for 2017 was the second highest value in the 108-year period record at more than double the average. Only 2012 had a higher USCEI value. …

    There were a record-tying 16 weather and climate disasters with losses exceeding $1 billion during 2017 including three tropical cyclones, eight severe storms, two inland floods, a crop freeze, drought and wildfires causing a total of 362 direct fatalities among these events…The cumulative costs for these 219 events exceed $1.5 trillion.

  5. Climate change impacts already locked in, but the worst can still be avoided

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    November 16, 2017 University of Exeter Read full ScienceDaily article here

    Some impacts of global warming — such as sea level rise and coastal flooding — are already locked in and unavoidable, according to a major research project.
    Global temperatures have already risen by around 1°C, and a further 0.5°C warming is expected. The full impacts of current warming have not yet been seen, since ice sheets and oceans take many decades to fully react to higher temperatures.

    But more severe impacts can still be avoided if global greenhouse gas emissions are reduced.

    More than 50 scientists from 16 institutions in 13 countries have worked on the HELIX project (High-End Climate Impacts and Extremes), which has just finished after four years. The project examined the possible effects of warming of 1.5°C, 2°C, 4°C and 6°C compared to pre-industrial levels.

    Even with rapid cuts in global greenhouse gas emissions keeping warming below 2°C, sea levels could rise by 0.5m by the end of the 21st Century, particularly affecting small island states and low-lying countries. HELIX calculations suggest this could impact 2.5 million in Bangladesh….

  6. Irma and Harvey — climate change is real

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    September 7 2017  Read full Washington Post Op-Ed here

    ….Hurricanes get their energy from warm ocean waters, and the oceans are warming because of the human-caused buildup of heat-trapping gases in the atmosphere, primarily from the burning of coal, oil and gas. The strongest hurricanes have gotten stronger because of global warming. Over the past two years, we have witnessed the most intense hurricanes on record for the globe, both hemispheres, the Pacific and now, with Irma, the Atlantic.

    We also know that warmer air holds more moisture, and the amount of water vapor in the atmosphere has increased because of human-induced global warming. We’ve measured this increase, and it has been unequivocally attributed to human-caused warming. That extra moisture causes heavier rainfall, which has also been observed and attributed to our influence on climate. We know that rainfall rates in hurricanes are expected to increase in a warmer world, and now we’re living that reality….\

    …Cutting-edge climate science suggests that such stalled weather patterns could result from a slowed jet stream, itself a consequence — through principles of atmospheric science — of the accelerated warming of the Arctic. This is a reminder of how climate changes in far-off regions such as the North Pole can have very real effects on extreme weather faced here in the Lower 48.

    These linkages are preliminary, and scientists are still actively studying them. But they are a reminder that surprises may be in store — and not welcome ones — when it comes to the unfolding effects of climate change….

  7. Deforestation has double the effect on global warming than previously thought

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    • Even if all fossil fuel emissions are eradicated, if current rates of deforestation in the tropics continue through to 2100 then there will still be a 1.5 degree Celsius increase in global temperature
    • While carbon dioxide emissions from energy use must be the primary target of climate change mitigation efforts, land use and land cover change (LULCC) also represent an important source of climate forcing.
    • Tackling deforestation should be higher on the climate change agenda.

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    In the fight against climate change, much of the focus rests on reducing our dependence on fossil fuels and developing alternative energy sources. However, the results of a new study suggest that far more attention should be paid to deforestation and how the land is used subsequently – the effects of which make a bigger contribution to climate change than previously thought.

    The research, conducted by Cornell University and published in the journal Environmental Research Letters,shows just how much this impact has been underestimated. Even if all fossil fuel emissions are eradicated, if current rates of deforestation in the tropics continue through to 2100 then there will still be a 1.5 degree Celsius increase in global temperature….

    Natalie M Mahowald et al. Are the impacts of land use on warming underestimated in climate policy? Environmental Research Letters. August 2017. DOI: 10.1088/1748-9326/aa836d

    Abstract: While carbon dioxide emissions from energy use must be the primary target of climate change mitigation efforts, land use and land cover change (LULCC) also represent an important source of climate forcing. In this study we compute time series of global surface temperature change separately for LULCC and non-LULCC sources (primarily fossil fuel burning), and show that because of the extra warming associated with the co-emission of methane and nitrous oxide with LULCC carbon dioxide emissions, and a co-emission of cooling aerosols with non-LULCC emissions of carbon dioxide, the linear relationship between cumulative carbon dioxide emissions and temperature has a two-fold higher slope for LULCC than for non-LULCC activities. Moreover, projections used in the Intergovernmental Panel on Climate Change (IPCC) for the rate of tropical land conversion in the future are relatively low compared to contemporary observations, suggesting that the future projections of land conversion used in the IPCC may underestimate potential impacts of LULCC. By including a “business as usual” future LULCC scenario for tropical deforestation, we find that even if all non-LULCC emissions are switched off in 2015, it is likely that 1.5°C of warming relative to the preindustrial era will occur by 2100. Thus, policies to reduce LULCC emissions must remain a high priority if we are to achieve the low to medium temperature change targets proposed as a part of the Paris Agreement. Future studies using integrated assessment models and other climate simulations should include more realistic deforestation rates and the integration of policy that would reduce LULCC emissions.

  8. Warming may quickly drive forest-eating beetles north, says study

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    • Pines in Canada and much of US at risk

    August 28, 2017 Lamont-Doherty Earth Observatory, Columbia University  read full ScienceDaily article here

    Over the next few decades, global warming-related rises in winter temperatures could significantly extend the range of the southern pine beetle — one of the world’s most aggressive tree-killing insects — through much of the northern United States and southern Canada, says a new study. The beetle’s range is sharply limited by annual extreme temperature lows, but these lows are rising much faster than average temperatures — a trend that will probably drive the beetles’ spread, say the authors. The study was published today in the journal Nature Climate Change.

    …Until recently, southern pine beetles lived from Central America up into the southeastern United States, but in the past decade or so they have also begun appearing in parts of the Northeast and New England…

    …”We could see loss of biodiversity and iconic regional forests. There would be damage to tourism and forestry industries in already struggling rural areas.” Coauthor Radley Horton, a researcher at Columbia University’s Lamont-Doherty Earth Observatory, said infested forests could also dry out and burn, endangering property and emitting large amounts of carbon into the atmosphere

    Corey Lesk, Ethan Coffel, Anthony W. D’Amato, Kevin Dodds, Radley Horton. Threats to North American forests from southern pine beetle with warming winters. Nature Climate Change, 2017; DOI: 10.1038/nclimate3375

  9. July 2017 equaled record July 2016 global warmth

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    From NASA’s Goddard Institute for Space Studies

    July 2017 was statistically tied with July 2016 as the warmest July in the 137 years of modern record-keeping, according to a monthly analysis of global temperatures by scientists at NASA‘s Goddard Institute for Space Studies (GISS) in New York.

    Last month was about 0.83 degrees Celsius warmer than the mean July temperature of the 1951-1980 period. Only July 2016 showed a similarly high temperature (0.82 °C), all previous months of July were more than a tenth of a degree cooler.

    Starting with this update, the previously used ocean data set ERSST v4 was replaced by the newer ERSST v5. This contributed to the changes of some of the data in last month’s update. For more information, see the Updates to Analysis and the History Pages.

    GISTEMP LOTI Anomaly July2017 A global map of the June 2017 LOTI (land-ocean temperature index) anomaly, relative to the 1951-1980 June average. View larger image.

    The monthly analysis by the GISS team is assembled from publicly available data acquired by about 6,300 meteorological stations around the world, ship- and buoy-based instruments measuring sea surface temperature, and Antarctic research stations.

    The modern global temperature record begins around 1880 because previous observations didn’t cover enough of the planet. Monthly analyses are sometimes updated when additional data becomes available, and the results are subject to change.

  10. 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