http://www.examiner.com/article/stud...g-20th-century
http://www.nature.com/nature/journal...ture17418.html
But, but, but... 40 years ago my local area had mild winters so we have to DO SOMETHING, or it will be global CATASTROPHE!!!! I mean, it SEEMS LIKE my tiny local area got more rain last summer than the previous winter so we have to DO SOMETHING!!!!
http://www.nature.com/nature/journal...ture17418.html
A new study published yesterday shows there hasn't been an increase in extreme rainfall and droughts during the 20th century, even as humans ramped up burning of fossil fuels (coal, oil) in the late 1800s. It also shows that previous centuries show much more extreme weather, even though carbon dioxide levels were far lower than today's. The study used marine sediments, tree rings, ice cores and mineral deposits to reconstruct weather patterns over the last 1,200 years.
Buried machinery in barn lot in South Dakota during the Dust Bowl, an agricultural, ecological, and economic disaster in 1936.
USDA, https://commons.wikimedia.org/wiki/F...akota_1936.jpg
The scientists behind the study examined the interaction between the climate and hydrological (water) cycle in the northern hemisphere. What they found was no evidence to support the United Nation's Intergovernmental Panel on Climate Change (IPCC) contention that "dry areas will become ever drier and wet ones wetter as the global temperature rises."
Dr Fredrik Charpentier Ljungqvist, the lead author and a palaeoclimatologist at Stockholm University, explains that climate reconstruction showed a "prominent seesaw pattern of alternating moisture regimes" that has been remained "consistent over the past twelve centuries." Ljungqvist writes in the journal Nature: "This strongly suggests that the instrumental period is too short to capture the full range of natural hydroclimate variability."
The climate records, which date back to Viking times, indicate the 20th century was "unexceptional for rainfall and droughts despite assumptions that global warming would trigger more wet and dry extremes." In fact, "several other centuries show stronger and more widespread extremes," lead author Fredrik Ljungqvist of Stockholm University told Reuters. "We can't say it's more extreme now."
This runs counter to what many climate models have been spitting out, and Ljungqvist says that's because they are based on "over-estimated assumptions that rising temperatures would make dry areas drier and wet areas wetter, with more extreme heatwaves, droughts, downpours and droughts." His reconstructions, based on four unique sets of climate records, shows otherwise.
The study notes that the 10th century was by far the wettest century in the reconstruction, a time "when the Vikings were carrying out raids across Europe and the Song dynasty took power in China." They also note the 12th century was warm and the 15th century cool, and both centuries were the driest. Their conclusions are based on 196 climate records and say that "variations in the sun's output were among factors driving natural shifts in the climate in past centuries." The IPCC has previously reported the sun plays a little to no role in climate variability.
The 12th century is notable as being part of the Medieval Warm Period, which lasted from 950 to 1250. This higher-than-normal warm spell was shortly followed by the Little Ice Age, which includes the unusually cool and dry 15th century. Since 1850, temperatures across the northern hemisphere have gradually warmed up as the Earth left the mini Ice Age that affected much of the northern hemisphere. Climate scientists not involved in the study said it showed how hard it is to create accurate climate models.
"This paper adds to the growing evidence that the simple paradigm of 'wet-gets-wetter, dry-gets-drier' under a warming climate does not apply over land areas," said Ted Shepherd, a professor at the University of Reading, who spoke to Reuters. It also shows the contrast in current climate models, which "generally show an intensification of the hydrological cycle and more extreme wet and dry spells during the 20th century."
The study points out that there is an "absence of evidence that weather patterns predicted for higher temperatures have actually taken place." Scientists have been trying to attribute extreme weather events to global warming, but this study shows that may be an academic undertaking that only occurs in computer simulations, and not in the real world. "Much of the change is not only driven by temperature, but some internal, more random variability," Ljungqvist says. "It's therefore very, very hard also to predict (precipitation extremes) with models."
The study's authors add the now-standard caveat that global warming is still occurring, but they "question some of the modelling and simulations which have been used to link climate and the water cycle." The EPA relies on computer models and simulations to justify many of their onerous and costly regulations.
Buried machinery in barn lot in South Dakota during the Dust Bowl, an agricultural, ecological, and economic disaster in 1936.
USDA, https://commons.wikimedia.org/wiki/F...akota_1936.jpg
The scientists behind the study examined the interaction between the climate and hydrological (water) cycle in the northern hemisphere. What they found was no evidence to support the United Nation's Intergovernmental Panel on Climate Change (IPCC) contention that "dry areas will become ever drier and wet ones wetter as the global temperature rises."
Dr Fredrik Charpentier Ljungqvist, the lead author and a palaeoclimatologist at Stockholm University, explains that climate reconstruction showed a "prominent seesaw pattern of alternating moisture regimes" that has been remained "consistent over the past twelve centuries." Ljungqvist writes in the journal Nature: "This strongly suggests that the instrumental period is too short to capture the full range of natural hydroclimate variability."
The climate records, which date back to Viking times, indicate the 20th century was "unexceptional for rainfall and droughts despite assumptions that global warming would trigger more wet and dry extremes." In fact, "several other centuries show stronger and more widespread extremes," lead author Fredrik Ljungqvist of Stockholm University told Reuters. "We can't say it's more extreme now."
This runs counter to what many climate models have been spitting out, and Ljungqvist says that's because they are based on "over-estimated assumptions that rising temperatures would make dry areas drier and wet areas wetter, with more extreme heatwaves, droughts, downpours and droughts." His reconstructions, based on four unique sets of climate records, shows otherwise.
The study notes that the 10th century was by far the wettest century in the reconstruction, a time "when the Vikings were carrying out raids across Europe and the Song dynasty took power in China." They also note the 12th century was warm and the 15th century cool, and both centuries were the driest. Their conclusions are based on 196 climate records and say that "variations in the sun's output were among factors driving natural shifts in the climate in past centuries." The IPCC has previously reported the sun plays a little to no role in climate variability.
The 12th century is notable as being part of the Medieval Warm Period, which lasted from 950 to 1250. This higher-than-normal warm spell was shortly followed by the Little Ice Age, which includes the unusually cool and dry 15th century. Since 1850, temperatures across the northern hemisphere have gradually warmed up as the Earth left the mini Ice Age that affected much of the northern hemisphere. Climate scientists not involved in the study said it showed how hard it is to create accurate climate models.
"This paper adds to the growing evidence that the simple paradigm of 'wet-gets-wetter, dry-gets-drier' under a warming climate does not apply over land areas," said Ted Shepherd, a professor at the University of Reading, who spoke to Reuters. It also shows the contrast in current climate models, which "generally show an intensification of the hydrological cycle and more extreme wet and dry spells during the 20th century."
The study points out that there is an "absence of evidence that weather patterns predicted for higher temperatures have actually taken place." Scientists have been trying to attribute extreme weather events to global warming, but this study shows that may be an academic undertaking that only occurs in computer simulations, and not in the real world. "Much of the change is not only driven by temperature, but some internal, more random variability," Ljungqvist says. "It's therefore very, very hard also to predict (precipitation extremes) with models."
The study's authors add the now-standard caveat that global warming is still occurring, but they "question some of the modelling and simulations which have been used to link climate and the water cycle." The EPA relies on computer models and simulations to justify many of their onerous and costly regulations.
But, but, but... 40 years ago my local area had mild winters so we have to DO SOMETHING, or it will be global CATASTROPHE!!!! I mean, it SEEMS LIKE my tiny local area got more rain last summer than the previous winter so we have to DO SOMETHING!!!!
Comment