Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Tag Archive: ocean

  1. Ship exhaust makes oceanic thunderstorms more intense

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    September 7, 2017 American Geophysical Union read full ScienceDaily article here

    Thunderstorms directly above two of the world’s busiest shipping lanes are significantly more powerful than storms in areas of the ocean where ships don’t travel, according to new research.

    A new study mapping lightning around the globe finds lightning strokes occur nearly twice as often directly above heavily-trafficked shipping lanes in the Indian Ocean and the South China Sea than they do in areas of the ocean adjacent to shipping lanes that have similar climates.

    The difference in lightning activity can’t be explained by changes in the weather, according to the study’s authors, who conclude that aerosol particles emitted in ship exhaust are changing how storm clouds form over the ocean….

    Joel A. Thornton, Katrina S. Virts, Robert H. Holzworth, Todd P. Mitchell. Lightning Enhancement Over Major Oceanic Shipping Lanes. Geophysical Research Letters, 2017; DOI: 10.1002/2017GL074982

  2. 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….

  3. Eclipse Days Bring High Tides; Extra-High Tides Are a Preview of Sea Level Rise

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    Post your photos here- iSeeChange August 21 2017 

    Rising sea levels are already starting to flood our coastal communities. You can spot signs of change on days when the tides are extra high – as they will be on August 21, 2017, the day of a total solar eclipse.

    Extra-High Tides Are a Preview of Sea Level Rise

    Enhanced high tides happen when the sun, Earth, and moon are in near-perfect alignment, as they are every month during the full and new moon phases. At those times, the moon and Sun’s gravity add up to an extra “pull” on the Earth, making our planet’s oceans bulge more than normal. Those extra-high tides can cause flooding in homes and streets along the coast, giving us a preview of how sea-level rise will affect our communities in the future.

    How You Can Help

    Take pictures of high tides and flooding on August 21. Where do you see flooding? How does flooding affect your routine?

  4. Atlantic/Pacific ocean temperature difference fuels drought and wildfires in CA and Southwest US; multi-year predictions possible

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    • New study shows that the large-scale difference between a warm Atlantic and relatively cold Pacific ocean temperatures plays a fundamental role in causing droughts, and enhancing wildfire risks in California and the southwest.
    • the Atlantic/Pacific temperature difference shows pronounced variations on timescales of more than 5 years. Like swings of a very slow pendulum, this implies that there is predictability in the large-scale atmosphere/ocean system, which we expect will have a substantial societal benefit.
    July 26, 2017 Institute for Basic Science Read full ScienceDaily article here
    A new study shows that difference in water temperature between the Pacific and the Atlantic oceans together with global warming impact the risk of drought and wildfire in southwestern North America.
    …”we were able to show that without anthropogenic effects, the droughts in the southwestern United States would have been less severe.”
    ..The new findings show that a warm Atlantic and a relatively cold Pacific enhance the risk for drought and wildfire in the southwestern US. “According to our study, the Atlantic/Pacific temperature difference shows pronounced variations on timescales of more than 5 years. Like swings of a very slow pendulum, this implies that there is predictability in the large-scale atmosphere/ocean system, which we expect will have a substantial societal benefit,”…
    …”we can use our climate computer model to determine whether on average the next year will have drier or wetter soils or more or less wildfires. Our yearly forecasts are far better than chance.”…

    Yoshimitsu Chikamoto, Axel Timmermann, Matthew J. Widlansky, Magdalena A. Balmaseda, Lowell Stott. Multi-year predictability of climate, drought, and wildfire in southwestern North America. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-06869-7

  5. Since 1950s, 8.3 billion tons of plastics produced; 79% discarded into landfills and environment; only 9% recycled

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    • Humans have created 8.3 billion metric tons of plastics since large-scale production of the synthetic materials began in the early 1950s, and most of it now resides in landfills or the natural environment, according to a study.

    Posted: 19 Jul 2017 11:09 AM PDT  read full ScienceDaily article here

    …The researchers found that by 2015, humans had generated 8.3 billion metric tons of plastics, 6.3 billion tons of which had already become waste. Of that waste total, only 9 percent was recycled, 12 percent was incinerated and 79 percent accumulated in landfills or the natural environment.

    If current trends continue, roughly 12 billion metric tons of plastic waste will be in landfills or the natural environment by 2050. Twelve billion metric tons is about 35,000 times as heavy as the Empire State Building.

    Most plastics don’t biodegrade in any meaningful sense, so the plastic waste humans have generated could be with us for hundreds or even thousands of years,” said Jenna Jambeck, study co-author and associate professor of engineering at UGA. “Our estimates underscore the need to think critically about the materials we use and our waste management practices.“…

    They estimated that 8 million metric tons of plastic entered the oceans in 2010….

    “Roughly half of all the steel we make goes into construction, so it will have decades of use — plastic is the opposite,” said Roland Geyer, lead author of the paper and associate professor in UCSB’s Bren School of Environmental Science and Management. “Half of all plastics become waste after four or fewer years of use.”

    “I think we need to take a careful look at our expansive use of plastics and ask when the use of these materials does or does not make sense.” ….

    Roland Geyer et al. Production, use, and fate of all plastics ever made. Science Advances, July 2017 DOI: 10.1126/sciadv.1700782

  6. Ocean temperature changes contributing to droughts

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    July 19, 2017 University of Exeter  see ScienceDaily article here

    Fluctuations in sea surface temperature are a factor in causing persistent droughts in North America and around the Mediterranean, new research suggests. A team from the universities of Exeter, Montpellier and Wageningen analysed data from 1957-2002 and found sea surface temperatures in the North Pacific and North Atlantic became increasingly variable, and extremes lasted for longer.

    Ocean temperatures are a major driver of conditions on land, and the researchers showed that the changes they observed correlated with increases in land temperature variability, and persistence of extreme temperatures. This in turn was associated with persistent droughts in North America and on land around the Mediterranean….

    “Our evidence shows that larger and more persistent variations in sea surface temperature have occurred in the North Atlantic and North Pacific and these contributed to more extreme and persistent temperature anomalies on parts of the world’s land surface,” said Professor Tim Lenton, of the University of Exete

    …”For instance, a long heatwave can have greater impacts on human mortality than the sum of individual hot days, and multi-year droughts can have greater agricultural economic impacts than the sum of individual dry years,” Professor Lenton said…

    Timothy M. Lenton, Vasilis Dakos, Sebastian Bathiany, Marten Scheffer. Observed trends in the magnitude and persistence of monthly temperature variability. Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-06382-x

  7. Hopes of mild climate change dashed by new research- doubling of CO2 could lead to 6C warming

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    • Planet could heat up far more than hoped as new work shows temperature rises measured over recent decades don’t fully reflect global warming already in the pipeline (in the oceans).
    • The new research shows the 4.5C upper limit for climate sensitivity (for a doubling of CO2 in the atmosphere) is real and could be as high as 6C.
    • The global temperature is likely to be 2.6C to 4.8C higher by the end of the century if emissions are not cut.

    ….how much global temperatures rise for a certain level of carbon emissions is called climate sensitivity and is seen as the single most important measure of climate change. Computer models have long indicated a high level of sensitivity, up to 4.5C for a doubling of CO2 in the atmosphere.the new work, using both models and paleoclimate data from warming periods in the Earth’s past, shows that the historical temperature measurements do not reveal the slow heating of the planet’s oceans that takes place for decades or centuries after CO2 has been added to the atmosphere.

    …The new research, published in the journal Science Advances, has ended that. “The worrisome part is that all the models show there is an amplification of the amount of warming in the future,” he said. The situation might be even worse, as Proistosescu’s work shows climate sensitivity could be as high as 6C.

    ….“The models simulate a warming pattern like today’s, but indicate that strong feedbacks kick in when the Southern Ocean and Eastern Equatorial Pacific eventually warm, leading to higher overall temperatures than would simply be extrapolated from the warming seen to date,” said [co-author] Peter Huybers…“But there is no perfect analogue for the changes that are coming.”

  8. New study confirms the oceans are warming rapidly

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    • Although there’s some uncertainty in the distribution among Earth’s ocean basins, there’s no question that the ocean is heating rapidly

    John Abraham Monday 26 June 2017 06.00 EDT  Guardian UK  Full article here

    ….The most important measurement of global warming is in the oceans. In fact, “global warming” is really “ocean warming.” If you are going to measure the changing climate of the oceans, you need to have many sensors spread out across the globe that take measurements from the ocean surface to the very depths of the waters. Importantly, you need to have measurements that span decades so a long-term trend can be established.

    These difficulties are tackled by oceanographers, and a significant advancement was presented in a paper just published in the journal Climate Dynamics. ….We found that regardless of whose data was used or where the data was gathered, the oceans are warming.

    …In the study, we looked at the different ways that three groups make decisions about mapping, bias, and climatology. We not only asked how much the oceans are warming, but how the warming differs for various areas (ocean basins) and various depths. We found that each ocean basin has warmed significantly. Despite this fact, there are some differences amongst the three groups. For instance, in the 300-700 meter oceans depths in the Pacific and Southern oceans, significant differences are exhibited amongst the tree groups. That said, the central fact is that regardless of how you measure, who does the measurements, when or where the measurements are taken, we are warming….. it will be important that we keep high-quality temperature sensors positioned throughout the oceans so in the future we will be able to predict where our climate is headed. We say in science that a measurement not made is a measurement lost forever. And there are no more important measurements than of heating of the oceans.

    Wang, G., Cheng, L., Abraham, J. et al. Consensuses and discrepancies of basin-scale ocean heat content changes in different ocean analyses Clim Dyn (2017). doi:10.1007/s00382-017-3751-5

    Abstract

    Inconsistent global/basin ocean heat content (OHC) changes were found in different ocean subsurface temperature analyses, especially in recent studies related to the slowdown in global surface temperature rise. This finding challenges the reliability of the ocean subsurface temperature analyses and motivates a more comprehensive inter-comparison between the analyses. Here we compare the OHC changes in three ocean analyses (Ishii, EN4 and IAP) to investigate the uncertainty in OHC in four major ocean basins from decadal to multi-decadal scales. First, all products show an increase of OHC since 1970 in each ocean basin revealing a robust warming, although the warming rates are not identical. The geographical patterns, the key modes and the vertical structure of OHC changes are consistent among the three datasets, implying that the main OHC variabilities can be robustly represented. However, large discrepancies are found in the percentage of basinal ocean heating related to the global ocean, with the largest differences in the Pacific and Southern Ocean. Meanwhile, we find a large discrepancy of ocean heat storage in different layers, especially within 300–700 m in the Pacific and Southern Oceans. Furthermore, the near surface analysis of Ishii and IAP are consistent with sea surface temperature (SST) products, but EN4 is found to underestimate the long-term trend. Compared with ocean heat storage derived from the atmospheric budget equation, all products show consistent seasonal cycles of OHC in the upper 1500 m especially during 2008 to 2012. Overall, our analyses further the understanding of the observed OHC variations, and we recommend a careful quantification of errors in the ocean analyses.

  9. Marine reserves help mitigate against climate change, say scientists

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    June 5, 2017 University of York  full ScienceDaily article here

    Highly protected marine reserves can help mitigate against the impacts of climate change, a study by a team of international scientists has concluded….The study….evaluated existing peer reviewed studies on the impact of marine reserves around the world.Currently, only 3.5 per cent of the ocean has been set aside for protection with just 1.6 per cent fully protected from exploitation. International groups are working to raise the total to 10 per cent by 2020, while delegates to the International Union for the Conservation of Nature’s 2016 World Conservation Congress agreed that at least 30 per cent should be protected by 2030.

    Scientists say Marine Reserves and Marine Protected Areas (MPAs):

    • Protect coasts from sea-level rise, storms and other extreme weather events
    • Help offset climate-change induced declines in ocean and fisheries productivity
    • Provide refuges for species as they adjust their ranges to changing conditions
    • Can help combat acidification

    Callum M. Roberts, Bethan C. O’Leary, Douglas J. McCauley, Philippe Maurice Cury, Carlos M. Duarte, Jane Lubchenco, Daniel Pauly, Andrea Sáenz-Arroyo, Ussif Rashid Sumaila, Rod W. Wilson, Boris Worm, and Juan Carlos Castilla. Marine reserves can mitigate and promote adaptation to climate change. PNAS, June 2017 DOI: 10.1073/pnas.1701262114

  10. Ocean temperature extremes lead to population declines- albatross

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    • the effect of extreme events can be buffered when species live in cooler than optimal environments, providing a kind of “climate safety margin” for those species.

    Posted: 30 May 2017 11:07 AM PDT See full article here: ScienceDaily

    …the journal Philosophical Transactions of the Royal Society B created a special June issue to explore what is known on [behavioral, ecological and evolutionary impacts of extreme climatic events] and pioneer new approaches to this challenging and rapidly expanding field of study…”Changes in variability can have very different consequences on population dynamics for both animals and plants,” Jenouvrier says…..

    …A change in temperature variability leads to more frequent warmer and colder events while a change in the temperature mean increases the occurrence of warmer events but decreases the occurrence of colder events. The researchers found that changes in the variation of ocean temperatures had a threefold effect on the growth rate of the albatross population compared to changes in just mean ocean temperature. Increasing variation of ocean temperatures — temperatures that range well below or above the optimum for the species — leads to population decline, while increasing the mean (average) of ocean temperatures result in population increase.

    … In other words, the effect of extreme events can be buffered when species live in cooler than optimal environments, providing a kind of “climate safety margin” for those species.

    “In this case, the historical mean (or average) of sea surface temperatures was lower than the optimal temperature for this species,” explains Jenouvrier. “If the mean temperature warms, these albatrosses will experience temperatures that will be more often at or near the optimum range for the species, so these changes in mean will buffer the negative effects of the extreme warming events.” However, even for those species that do experience a buffering effect from the climate safety margin, it’s likely to be only temporary as future temperatures continue to rise beyond their optimal temperature range, she adds….

    Martijn van de Pol, Stéphanie Jenouvrier, Johannes H. C. Cornelissen, Marcel E. Visser. Behavioural, ecological and evolutionary responses to extreme climatic events: challenges and directions. Philosophical Transactions of the Royal Society B: Biological Sciences, 2017; 372 (1723): 20160134 DOI: 10.1098/rstb.2016.0134.