Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Tag Archive: warming

  1. Methane: Importance to Global Warming & Understanding Emission Sources – Webinar for Point Blue by Professor Robert Howarth, Cornell

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    • We need to stop use of natural gas (esp. dramatic increase in shale gas/fracking) because of methane leaks and the accelerated risks of reaching climatic tipping points.
    • The dramatic methane increase over the past decade is not from cows.

    March 19, 2018 Webinar presentation by Professor Robert Howarth, PhD to Point Blue

    We were very fortunate to have Professor Bob Howarth of Cornell University, the David R. Atkinson Professor of Ecology & Environmental Biology, present an excellent webinar for Point Blue scientists on climate change and methane last week.  Below is a link to the recording and here is a link to a pdf of the presentation: Howarth Methane and global change — Point Blue Conservation Science — March 19 2018 pdf.

    See Zoom Recording here (306 MB)

    Howarth Methanecows and methane March 2018 Howarth

  2. Increased risk of a shutdown of ocean convection posed by warm North Atlantic summers; increased freshwater flow into ocean already weakening subpolar deep convection

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    • Long-term observations show that increased surface freshening has weakened deep water convection in the subpolar North Atlantic.
    • There is a clear correlation between the sea surface temperatures in the Irminger Sea in summer, the amount of surface freshwater in this region— and the atmospheric conditions and onset of convection in the following winter.
    • [Note: this could have devastating impacts on weather -see this study for example.]

    March 13, 2018 Helmholtz Centre for Ocean Research Kiel (GEOMAR) Read full ScienceDaily article here’

    [Also see: The fast-melting Arctic is already messing with the ocean’s circulation, scientists say by Chris Moony March 14 2018 Washington Post]

    The temperature and salinity of seawater are key drivers for the global ocean circulation system. Warm and saline water transported poleward cools at the surface when it reaches high latitudes and becomes denser and subsequently sinks into the deep ocean. This process is called convection. At depth, the water is circulated back towards the equator drawing new water masses behind it. Deep convection occurs only in a few regions around the globe, including the Irminger Sea and the Labrador Sea near Greenland. But what happens if additional freshwater, for example from melting glaciers, enters this system? Model calculations predict a possible weakening of deep convection, but so far this could not be confirmed by direct observations.

    By using long-term observations, scientists … have now shown that freshwater has already impacted convection in the last decade. The results have been published in the international journal Nature Climate Change….

    …”In case that warm summers with increased surface freshwater occur within extended warm periods, the ocean loses less heat in the following winter. As a result, the fresh surface layer that formed in summer remains stable for a longer time resulting in a delayed onset of convection,” says Dr. Oltmanns.

    Marilena Oltmanns, Johannes Karstensen, Jürgen Fischer. Increased risk of a shutdown of ocean convection posed by warm North Atlantic summers. Nature Climate Change, 2018; DOI: 10.1038/s41558-018-0105-1

  3. Arctic Spring Is Starting 16 Days Earlier than a Decade Ago, Study Shows

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    by Jonathan Watts March 2 2018 read full Guardian UK article here

    The Arctic spring is arriving 16 days earlier than it did a decade ago, according to a new study which shows climate change is shifting the season earlier more dramatically the further north you go. The research…comes amid growing concern about the warming of Greenland, Siberia, Alaska and other far northern regions, which have recently experienced unusually prolonged and frequent midwinter temperature spikes.

    …“Spring is arriving earlier, and the Arctic is experiencing greater advances of spring than lower latitudes,” said lead author Eric Post, a fellow of the John Muir Institute and polar ecologist at UC Davis….

    Eric Post, Byron Steinman and Michael Mann. Acceleration of phenological advance and warming with latitude over the past century. Scientific Reports volume 8, Article number: 3927 (2018) doi:10.1038/s41598-018-22258-0

  4. In 2017, the oceans were by far the hottest ever recorded

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    • Researcher found that the upper 2000 meters (more than 6000 feet) of ocean waters were far warmer in 2017 than the previous hottest years 2013-2016.
    • It turns out that 2017 was a record-breaking year, 1.51 × 1022 Joules hotter than any other year. For comparison, the annual electrical generation in China is 600 times smaller than the heat increase in the ocean.

    by John Abraham 26 January 2018 read full Skeptical Science post here

    Among scientists who work on climate change, perhaps the most anticipated information each year is how much the Earth has warmed. That information can only come from the oceans, because almost all heat is stored there. If you want to understand global warming, you need to first understand ocean warming.

    This isn’t to say other measurements are not also important. For instance, measurements of the air temperature just above the Earth are really important. We live in this air; it affects us directly. A great commentary on 2017 air temperatures is provided by my colleague Dana Nuccitelli. Another measurement that is important is sea level rise; so too is ocean acidification. We could go on and on identifying the markers of climate change. But in terms of understanding how fast the Earth is warming, the key is the oceans.

    This important ocean information was just released today by a world-class team of researchers from China. The researchers (Lijing Cheng and Jiang Zhu) found that the upper 2000 meters (more than 6000 feet) of ocean waters were far warmer in 2017 than the previous hottest year. We measure heat energy in Joules. It turns out that 2017 was a record-breaking year, 1.51 × 1022 Joules hotter than any other year. For comparison, the annual electrical generation in China is 600 times smaller than the heat increase in the ocean.

    The authors provide a long history of ocean heat, going back to the late 1950s. By then there were enough ocean temperature sensors to get an accurate assessment of the oceans’ warmth. Their results are shown in the figure below. This graph shows ocean heat as an “anomaly,” which means a change from their baseline of 1981–2010. Columns in blue are cooler than the 1981-2010 period, while columns in red are warmer than that period. The best way to interpret this graph is to notice the steady rise in ocean heat over this long time period.

    OHC

    Ocean heat content change since 1958. Illustration: Cheng and Zhu (2018), Advances in Atmospheric Sciences

    ….It’s interesting to look at the top five years on record in terms of ocean heat; they are listed below.

      1. 2017: 19.19 × 1022 J
      2. 2015: 17.68 × 1022 J
      3. 2016: 17.18 × 1022 J
      4. 2014: 16.74 × 1022J
      5. 2013: 16.08 × 1022 J

    Note that these are the five hottest years ever recorded. Truly astonishing.

    Cheng, L. & Zhu, J. 2017 was the warmest year on record for the global ocean. Adv. Atmos. Sci. (2018) 35: 261. https://doi.org/10.1007/s00376-018-8011-z

  5. 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

  6. 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

  7. 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.”

  8. 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.

  9. 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….

  10. 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….