Projecting the Frequency of Heat Waves in the 21st Century over the Paris Basin

by Amelia Hamiter

The high mortality of the 2003 heat wave in France, and its particularly severe impact in the Paris basin, has drawn attention to the importance of considering heat wave occurrences of the future. Evaluating heat waves in the Paris region from 1951-2009 and using several climate change and emissions scenarios to model future heat wave possibilities, Lemonsu et al. (2014) predict that the frequency of heat wave occurrences in the target area will increase systematically with time and global warming, and that the durations of these heat waves will grow. Continue reading

How Climate Change Affects Women in Ghana

by Phoebe Shum

Who knew that gender bias could exist even in a topic such as climate change?

According to the UN, women are most vulnerable to climate change due to their role in food production. After all, 70% of the world’s farmers are women, and these women produce 60-80% of the world’s food crops. Trish Glazebrook (2011), Philosophy Professor from Dalhousie University in Nova Scotia, explains how climate change particularly affects women subsistence farmers in areas of poverty. In northeast Ghana, the successful growing of crops is highly dependent on the rainy season due to the lack of irrigation technology. The rainy season is the only growing cycle per year, and when anthropogenic climate change causes extreme and abnormal weather conditions like droughts and floods, farming patterns are altered and the women are not able to provide subsistence for their families. Land degradation, desertification and soil erosion heavily affect the women, and the many people they provide for. On average, one woman can be responsible for 6 to 17 people, from children to the elderly to the sick to the handicapped. Their survival heavily depends on natural resources. Continue reading

Resilience or Decline of Species under Climate Change?

by Samantha Thompson

Species have widely been affected by changes in global climate but to what extent is uncertain, though predictions of species decline are often urgent. For example, one prominent analysis predicted that 15 to 37% of species would be endangered or extinct by 2050 (Moritz, 2013). Another predicts more than a 50% loss of climatic range by 2080 for some 57% of widespread species of plants and 34% of animals (Moritz, 2013). Montane taxa are expected to lose range area as they shift northward with warming (Moritz, 2013). Craig Moritz et al. point out that fossil records suggests that most species have persisted through past climate change, whereas forecasts of future impacts predict large-scale range reduction and extinction. Moritz et. al. explore the apparent contradiction between observed past and predicted future species responses summarizing salient concepts and theories and by reviewing broad-scale predictions of future response and evidence from paleontological and phylogeographic studies of past responses at millennial or greater time scales. Bringing the two ideas together, the authors consider evidence for species responses to recent twentieth century climate changes and place them in a management context. Continue reading

Who Loses from Climate Change Effects on Agriculture? Who Wins?

by Caroline Vurlumis

Anthropogenic climate change may lead to more extreme weather events and will impact human health and the economy. One of the most important effects of climate change however is its impact on agriculture and the human population. Using ecological niche modeling (ENM), a technique to relate species presence to environmental factors, Beck (2013) sought to model suitability of agriculture in different regions based on soil conditions and climate. He applied this general and simple model for agriculture across the Old World (defined as Asia, Africa and Europe) and the Australia/Pacific region to create model scenarios of agriculture for the year 2050 and determined which countries would win or lose from climate change in the agricultural sector; different regions vary considerably in agricultural suitability which cannot simply be determined by a country’s wealth. Beck’s model predicted that parts of Europe, Africa and southern and eastern Asia will have a negative impact while north-eastern Europe and the Tibetan plateau will benefit. Continue reading

Extreme Temperature and Precipitation in the Caribbean Intensifying

by Tim Storer

Climate change is an enormously complex subject, but thankfully copious temperature and precipitation data exist from around the globe that allow for detailed analyses of global and local patterns. In many parts of the globe, increasing trends in weather intensity have been observed, and the most recent data analysis of Caribbean weather reaffirms increased weather intensity throughout the last fifty years (Stephenson et al. 2013). There have been strong rising trends in surface temperatures at several land weather stations throughout the region, but much weaker trends in precipitation than those related to temperature. Still, there were trends of increased average yearly and daily rainfall. The Caribbean region is especially noteworthy because of its high potential for damage related to climate change and high intensity weather events. Continue reading

Comets, Climate Change, and Extinctions—2

 

by Emil Morhardt

When a large meteorite struck the earth 65 million years ago, it killed off the dinosaurs by abrupt climate change; the energy of the strike sharply raised global temperatures, ignited massive wildfires, and filled the atmosphere both with smoke from the fires and dust ejected from the crater which presumably prevented plants from thriving for a long enough time to starve all but the smallest animals (allowing, as it happened, the evolution of humans.) That’s a different cause of climate change than now, and most of us, if we worry about climate change at all, don’t much worry about it being caused by another meteorite strike. But, on August 16, I wrote about a paper published in 2007 that proposed a similar, though not so severe, extraterrestrial impact and abrupt climate change about 12,800 years ago—the initiation of the Younger Dryas (YD) cooling episode that stopped the Continue reading

Temperature Drives the Continental-Scale Distribution of Key Microbes in Topsoil Communities

by Elizabeth Medford

While it has become fairly well known that global warming will cause plant and animal species to migrate toward cooler areas or cause range loses, until now it has been unclear whether this will also be true for microorganisms. Microorganisms play a key role in soil fertility and erodibility making this study relevant both for future agricultural endeavors as well as future efforts relating to ecological protection. Garcia-Pitchel et al. (2013) conducted continental-scale compositional surveys of soil crust microbial communities in the arid regions of North America. The results from these surveys imply that temperature caused latitudinal replacement between two key topsoil cyanobacteria. The cyanobacteria Microcoleus vaginatus behaved more psychrotolerant and less thermotolerant while M. steenstrupii behaved more thermotolerant. These results imply that the later may replace the former as temperature increases globally. Further studies are required to fully understand the impact of this microbial replacement. Continue reading

Asian Tiger Mosquito Targets Humans and Pets

by Emil Morhardt

As a follow-on to the previous post, this paper was just published a week ago and makes it clear that all the targets of Asian Tiger Mosquitos—transmitters of dengue, La Crosse, and chikungunya viruses in the Northeastern US—are mammals, and most of them are humans, cats, and dogs. Humans were targeted more in the suburbs, and cats in the cities. This is quite different from Culex mosquitos, another major vector of human diseases, which primarily feed on birds. Ari Faraji and his coauthors found this out by trapping mosquitos in central New Jersey, then sequencing the DNA in their blood meals. Mammalian blood constituted 84% of the meals, with humans making up 52%, cats 21%, and dog 12%. The rest came from mammals also, including, opossums, squirrels, rabbits, and deer.

Central New Jersey is at the northern limit of these mosquitos at the moment, but climate Continue reading

Elevated Temperatures Increase Toxicity of Copper but Decrease that of Oxytetracycline in a Marine Protozoan

by Emil Morhardt

One aspect of increased ocean temperatures is that they may alter the resistance of marine organisms to pollutants. In a paper just published, such was found to be case for the marine protozoan, Euplotes crassus, that lives on the ocean floor where particulate pollutants get deposited. The protozoans were exposed to two common pollutants—the organic antibiotic oxytetracycline, and the potentially toxic metal, copper—over a range of temperatures. The scientists looked at their effects on survival rate, replication rate, feeding rate (endocytosis) and general of toxic stress (measured as lysosomal membrane stability) all interrelated. Increasing the concentrations of both these toxicants decreased all four measures of protozoan well-being, but in almost all cases Continue reading

Interglacial Sea Levels and their Effects on Coral Reefs

     
Fossil reefs can be used as climate proxies to determine previous climate conditions and provide insight into the resulting reactions of reef ecosystems to changes in temperature. There are data that suggest the existence of a significant increase in sea level during the last interglacial period, approximately 121 thousand years ago, when ice sheet<!–[if supportFields]> XE “ice sheet” <![endif]–><!–[if supportFields]><![endif]–> levels were unsustainable and shrunk considerably. Blanchon et al. 2009 used samples of fossilized reef from the northeast coast of the Yucatán peninsula, Mexico, to measure reef reactions to increased sea levels. They found that because of the glacial melt, sea level had risen approximately 4–6 meters higher than current levels, and with it, the height of the corals. When sea levels decreased, the reef back stepped in reaction, or essentially died, approximately 6 meters above currfent sea level. These data provide reason to assume that a similar reaction is likely to occur among modern coral<!–[if supportFields]> XE “coral” <![endif]–><!–[if supportFields]><![endif]–> reefs with increases in temperature.
. — Lauren Orme    
Blanchon, P., Eisenhauer, A., Fietzke, J., Liebetrau, V. 2009. Rapid sea-level rise and reef back-stepping at the close of the last interglacial highstand. Nature. 458. 881–884.

 The age structure of a well-exposed fossil coral is analyzed through its stratigraphic architecture and palaeoecologic zonation. The northern peninsula of the Yucatán has no neotectonic activity. It’s well preserved coral structures date into the Miocene and Pleistocene eras. Global climate change has resulted in dramatic and rapid melting of ice shelves in both Antarctic and Greenland ice sheet areas. The affirmation by this projection of sea level instability has caused concern for the future of coral reefs, which are once again threatened by significant sea level rise due to anthropogenically caused climate change and are already threatened by other anthropogenic activity.