Science Alert January 1, 2021 Researchers at the University of Florida reviewed recent research on the Amazon rainforest to reach a grim conclusion. Lengthening dry seasons will soon no longer allow the rainforest canopies the five years they need in between dry seasons to recover from fires, allowing flammable grasses and shrubs to take over. Southern Amazonia can expect to reach a tipping point sometime before 2064 at the current rate of dry season lengthening. Like dominos, models predict once 30-50 percent deforestation is reached in the south, this will decrease the amount of rain by up to 40 percent […]
Tag Archives: global warming
The natural ‘Himalayan aerosol factory’ can affect climate
Science Daily December 7, 2020 Pre-industrial aerosol concentration and composition particles formed directly in the atmosphere from gaseous precursors, constitutes a large uncertainty in the anthropogenic radiative forcing. From their observations taken at the remote Nepal Climate Observatory Pyramid station at 5,079 m above sea level an international team of researchers (Finland, Italy, Switzerland, France, Estonia, USA – industry) shows that up-valley winds funnel gaseous aerosol precursors to higher altitudes. During this transport, these are oxidized into compounds of very low volatility, which rapidly form many aerosol particles. These are transported into the free troposphere, suggesting that the whole Himalayan region […]
Shift in atmospheric rivers could affect Antarctic sea ice, glaciers
Science Daily November 23, 2020 Researchers at UCLA investigated the atmospheric river (AR) frequency trends over the Southern Hemisphere using three reanalyses and two Community Earth System Model (CESM) ensembles. Their results show that AR frequency has been increasing over the Southern Ocean and decreasing over lower latitudes in the past four decades and that ARs have been shifting poleward. While the observed trends are mostly driven by the poleward shift of the westerly jet, the experiments indicate anthropogenic forcing would result in positive AR frequency trends over the Southern Ocean due mostly to moisture changes. They conclude that the […]
Engineering a Way Out of Climate Change: Genetically Modified Organisms Could be the Key
Technology.org November 17, 2020 An international team of researchers (USA – Boston University, UC Santa Barbara, industry, DOE, UC Berkeley, Harvard Medical School, Arizona State University, University of Washington, Woods Hole, Colorado State University, MIT, Cornell University, Oak Ridge National Laboratory, Israel) has identified the possible ways in which synthetic and systems biology (SSB) could be used to reduce greenhouse gas. According to the researchers the range of possibilities include: Engineer plants to reduce atmospheric CO2, Identify genes that control the distribution of Biomass, Genetically modify the Root-to-Shoot ratio of Plants, Engineer plants to increase productivity, Engineer plants to Self-Fertilize, […]
New technique seamlessly converts ammonia to green hydrogen
Phys.org November 18, 2020 A team of researchers in the US (Northwestern University, industry) built a unique electrochemical cell with a proton-conducting membrane and integrated it with an ammonia-splitting catalyst to convert ammonia to hydrogen. The ammonia encounters the catalyst that splits it into nitrogen and hydrogen which is immediately converted into protons; protons are electrically driven across the proton-conducting membrane in the electrochemical cell. Continually pulling off the hydrogen drives the reaction to go further than it would otherwise. By removing hydrogen the reaction is pushed forward, beyond what the ammonia-splitting catalyst can do alone. The technique is a […]
Artificial intelligence reveals hundreds of millions of trees in the Sahara
EurekAlert October 20, 2020 A large proportion of dryland trees and shrubs grow in isolation, without canopy closure. These non-forest trees have a crucial role in biodiversity, and provide ecosystem services such as carbon storage, food resources and shelter for humans and animals. An international team of researchers (Denmark, USA – NASA Goddard Space Flight Center, Germany, France, Senegal, Belgium) mapped the crown size of each tree more than 3 m in size over a land area that spans 1.3 million km in the West African Sahara, Sahel and sub-humid zone. They detected over 1.8 billion individual trees. Although the […]
Geoengineering is just a partial solution to fight climate change
Science Daily July 20, 2020 In theory, spraying sulfur dioxide into the upper atmosphere at different locations, to form sulfuric acid clouds that block some solar radiation, could be adjusted every year to keep global warming at levels set in the Paris goals. According to a team of researchers in the US (UC Davis, UC Berkeley) no single technology to combat climate change will fully address the growing crisis, and we need to stop burning fossil fuels and aggressively harness wind and solar energy to power society ASAP. The regional impacts of geoengineering, including on precipitation and the Antarctic ozone […]
A Devastating US ‘Dust Bowl’ Is Twice as Likely Now Than During The Great Depression
Science Alert May 19, 2020 During 1930s Dust Bowl drought across North America’s Great Plains caused widespread crop failures, large dust storms and considerable out-migration. This coincided with the central United States experiencing its hottest summers of the twentieth century in 1934 and 1936, with over 40 heatwave days and maximum temperatures surpassing 44 °C at some locations. According to an international team of researchers (Australia, UK, Sweden) heatwave activity in similarly rare events would be much larger under today’s atmospheric green house gas forcing the return period of a 1-in-100-year heatwave summer (as observed in 1936) would be reduced to […]
Potentially fatal combinations of humidity and heat are emerging across the globe
Science Daily May 8, 2020 Humans’ ability to efficiently shed heat has enabled us to range over every continent, but a wet-bulb temperature (TW) of 35°C marks our upper physiological limit, and much lower values have serious health and productivity impacts. An international team of researchers (USA – Caltech. Columbia University, UK) found that a comprehensive evaluation of weather station data shows that some coastal subtropical locations have already reported a TW of 35°C and that extreme humid heat overall has more than doubled in frequency since 1979. The most extreme humid heat is highly localized in both space and […]
Amazon rainforest could be gone within a lifetime
Science Daily March 10, 2020 Regime shifts can abruptly affect hydrological, climatic and terrestrial systems, leading to degraded ecosystems and impoverished societies. Researchers in the UK analysed empirical data from terrestrial, marine and freshwater environments and show positive sub-linear empirical relationships between the size and shift duration of systems. Each additional unit area of an ecosystem provides an increasingly smaller unit of time taken for that system to collapse, meaning that large systems tend to shift more slowly than small systems but disproportionately faster. They substantiated these findings with five computational models that reveal the importance of system structure in […]