7 March 2016, Climate News Network, Climate query as US tornado risk rises. Scientists say the climate behaves too capriciously for them to know for sure whether global warming caused by burning fossil fuels is to blame for a growing tornado threat. Tornadoes in the US are getting worse, with the numbers in any one outbreak and the hazard of ever more frequent outbreaks both on the increase. And although climate change driven by global warming from human causes is under suspicion, nobody really knows for sure whether that is driving the pattern of change. But change is certainly happening. New research published in Nature Communications has examined the pattern of outbreaks and found that the average number of tornadoes in any one outbreak has increased since 1954, and the chance of extreme – and therefore extremely destructive – outbreaks has also increased. An outbreak is a large-scale weather event that can last for days, span huge regions and spawn multiple tornadoes. Continental America is used to these outbreaks, which is why a band of territory that spans central Texas, Illinois and Indiana, and embraces parts of Oklahoma, Kansas, Nebraska, Colorado and South Dakota, is known as Tornado Alley. Read More here
Tag Archives: Extreme Events
6 March 2016, Climate News Network, Risk level rises for North American forests. The speed at which the climate is changing is outstripping forests’ ability to adapt to drier, hotter conditions across vast swathes of the US and Canada. Drought and climate change are now threatening almost all the forests of the continental US, according to new research. Scientists from 14 laboratories and institutions warn in the journal Global Change Biology that climate is changing faster than tree populations can adapt. Existing forests, effectively and literally rooted to the spot, are experiencing conditions hotter and less reliably rainy than those in which they had evolved. “Over the last two decades, warming temperatures and variable precipitation have increased the severity of forest droughts across much of the continental United States,” says James Clark, professor of global environmental change at Duke University, North Carolina. He and colleagues synthesised hundreds of studies to arrive at a snapshot of changing conditions and a prediction of troubles ahead. Ominous predictions Other research has already delivered ominous predictions for the forests of the US southwest, but the scientists warn that other, normally leafier parts of the continent face increasing stress. Dieback, bark beetle infestation and wildfire risk may no longer be confined to the western uplands. “While eastern forests have not experienced the types of changes seen in western forests in recent decades, they too are vulnerable to drought and could experience significant changes with increased severity, frequency, or duration in drought,” the authors say. Professor Clark puts it more bluntly: “Our analysis shows virtually all US forests are now experiencing change and are vulnerable to future declines. Given the uncertainty in our understanding of how forest species and stands adapt to rapid change, it’s going to be difficult to anticipate the type of forests that will be here in 20 to 40 years.” Read More here
1 March 2016, Science Daily, Impact of climate change on public health. Health consequences of climate change: Doctors urge action to help mitigate risks and prepare for new challenges. Climate change is already having a noticeable impact on the environment and global health. Around the world extreme weather events, increased temperatures, drought, and rising sea levels are all adversely affecting our ability to grow food, access clean water, and work safely outdoors. Soon in some areas, the transformation will be so drastic and devastating that native populations will be displaced and forced to find new homes as environmental refugees. In a review published in theAnnals of Global Health, doctors warn of the impending public health crisis brought on by climate change and call for action to help prepare the world for what is ahead. As we begin to experience an unprecedented shift in temperature, we are starting to see the immense impact climate change will have on people around the world, especially those living in low-income countries. Bearing the brunt of the damage caused by climate change, low-income nations are especially susceptible because their economies often rely solely on agriculture and most do not possess the resources to ease the risks posed by climate events. Low-income countries contribute just a tiny fraction of greenhouse gases (GHG), yet, they stand to lose the most if something is not done to curb emissions. In 2004, the United States, Canada, and Australia approached 6 metric tons (mt) of GHG per capita, while per-capita GHG emissions in low-income countries was only 0.6 mt overall. “As global temperature increases, rich countries’ economies continue to prosper, but the economic growth of poor countries is seriously impaired,” explained co-author Barry S. Levy, MD, MPH, Adjunct Professor, Department of Public Health and Community Medicine, Tufts University School of Medicine. “The consequences for economic growth in poor countries will be substantial if we continue on a ‘business-as-usual’ path of increasing carbon dioxide concentrations and rapid climate change, with poor countries’ mean annual growth rate decreasing from 3.2% to 2.6%.” Read More here
15 February 2016, Science Daily, Four billion people affected by severe water scarcity. There are four billion people worldwide who are affected by severe water scarcity for at least one month a year. That is the conclusion of University of Twente Professor of Water Management, Arjen Hoekstra, after many years’ extensive research. This alarming figure is much higher than was previously thought. His ground-breaking research was published in Science Advances. Professor Hoekstra’s team is the first research group in the world to identify people’s water footprint from month to month and to compare it to the monthly availability of water. “Up to now, this type of research concentrated solely on the scarcity of water on an annual basis, and had only been carried out in the largest river basins,” says Hoekstra. He defines severe water scarcity as the depletion of water in a certain area. “Groundwater levels are falling, lakes are drying up, less water is flowing in rivers, and water supplies for industry and farmers are threatened. In this research, we established the maximum sustainable ‘water footprint’ for every location on earth, and then looked at actual water consumption. If the latter is much greater than what is sustainable, then there can be said to be severe water scarcity.” More than previously thought Until now, it had always been assumed in the scientific community that 2 to 3 billion people were affected by severe water scarcity. “Previous research looked at the availability of water on an annual basis, but that paints a more rosy and misleading picture, because water scarcity occurs during the dry period of the year,” explains Hoekstra. In his research, he describes for each place the number of months in a year that people are affected by severe water scarcity. That varies from zero to twelve months per year. Problem areas Of the four billion people referred to, a large proportion feel the effects of water scarcity directly. Particularly in Mexico, the western US, northern and southern Africa, southern Europe, the Middle East, India, China, and Australia, households, industries and farmers regularly experience water shortages. In other areas, water supplies are still fine but at risk in the long-term. Read More here