Thin Snowpack in West Signals Summer of Drought
http://www.nytimes.com/2013/02/23/us/in-drought-stricken-heartland-snow-is-no-savior.html?_r=0
http://www.nytimes.com/2013/02/23/us/in-drought-stricken-heartland-snow-is-no-savior.html?_r=0
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Climate Change
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Romulus
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I hate to read that. As you know, Texas has had two really bad drought seasons in a row--all kinds of fire damage.
Kapnick SB, Delworth TL. Controls of Global Snow Under a Changed Climate. Journal of Climate. An Error Occurred Setting Your User Cookie
This study assesses the ability of a newly developed high-resolution coupled model from the Geophysical Fluid Dynamics Laboratory to simulate the cold-season hydroclimate in the present climate, and examines its response to climate change forcing. Output is assessed from a 280-yr control simulation based on 1990 atmospheric composition and an idealized 140-yr future simulation where atmospheric CO2 increases at 1% yr?1 until doubling in year 70 and then remains constant.
When compared to a low-resolution model, the high-resolution model is found to better represent the geographic distribution of snow variables in the present climate. In response to idealized radiative forcing changes, both models produce similar global-scale responses where global-mean temperature and total precipitation increase while snowfall decreases. Zonally, snowfall tends to decrease in the low to mid latitudes and increase in the mid to high latitudes.
At the regional scale, the high and low-resolution models sometimes diverge in the sign of projected snowfall changes; the high-resolution model exhibits future increases in a few select high altitude regions, notably the northwestern Himalaya region and small regions in the Andes and southwestern Yukon. Despite such local signals, there is an almost universal reduction in snowfall as a percent of total precipitation in both models. Using a simple multivariate model, temperature is shown to drive these trends by decreasing snowfall almost everywhere while precipitation increases snowfall in the high altitudes and mid to high latitudes. Mountainous regions of snowfall increases in the high-resolution model exhibit a unique dominance of the positive contribution from precipitation over temperature.
This study assesses the ability of a newly developed high-resolution coupled model from the Geophysical Fluid Dynamics Laboratory to simulate the cold-season hydroclimate in the present climate, and examines its response to climate change forcing. Output is assessed from a 280-yr control simulation based on 1990 atmospheric composition and an idealized 140-yr future simulation where atmospheric CO2 increases at 1% yr?1 until doubling in year 70 and then remains constant.
When compared to a low-resolution model, the high-resolution model is found to better represent the geographic distribution of snow variables in the present climate. In response to idealized radiative forcing changes, both models produce similar global-scale responses where global-mean temperature and total precipitation increase while snowfall decreases. Zonally, snowfall tends to decrease in the low to mid latitudes and increase in the mid to high latitudes.
At the regional scale, the high and low-resolution models sometimes diverge in the sign of projected snowfall changes; the high-resolution model exhibits future increases in a few select high altitude regions, notably the northwestern Himalaya region and small regions in the Andes and southwestern Yukon. Despite such local signals, there is an almost universal reduction in snowfall as a percent of total precipitation in both models. Using a simple multivariate model, temperature is shown to drive these trends by decreasing snowfall almost everywhere while precipitation increases snowfall in the high altitudes and mid to high latitudes. Mountainous regions of snowfall increases in the high-resolution model exhibit a unique dominance of the positive contribution from precipitation over temperature.
Smith LC, Stephenson SR. New Trans-Arctic shipping routes navigable by midcentury. Proceedings of the National Academy of Sciences. New Trans-Arctic shipping routes navigable by midcentury
Recent historic observed lows in Arctic sea ice extent, together with climate model projections of additional ice reductions in the future, have fueled speculations of potential new trans-Arctic shipping routes linking the Atlantic and Pacific Oceans. However, numerical studies of how projected geophysical changes in sea ice will realistically impact ship navigation are lacking. To address this deficiency, we analyze seven climate model projections of sea ice properties, assuming two different climate change scenarios [representative concentration pathways (RCPs) 4.5 and 8.5] and two vessel classes, to assess future changes in peak season (September) Arctic shipping potential. By midcentury, changing sea ice conditions enable expanded September navigability for common open-water ships crossing the Arctic along the Northern Sea Route over the Russian Federation, robust new routes for moderately ice-strengthened (Polar Class 6) ships over the North Pole, and new routes through the Northwest Passage for both vessel classes. Although numerous other nonclimatic factors also limit Arctic shipping potential, these findings have important economic, strategic, environmental, and governance implications for the region.
Recent historic observed lows in Arctic sea ice extent, together with climate model projections of additional ice reductions in the future, have fueled speculations of potential new trans-Arctic shipping routes linking the Atlantic and Pacific Oceans. However, numerical studies of how projected geophysical changes in sea ice will realistically impact ship navigation are lacking. To address this deficiency, we analyze seven climate model projections of sea ice properties, assuming two different climate change scenarios [representative concentration pathways (RCPs) 4.5 and 8.5] and two vessel classes, to assess future changes in peak season (September) Arctic shipping potential. By midcentury, changing sea ice conditions enable expanded September navigability for common open-water ships crossing the Arctic along the Northern Sea Route over the Russian Federation, robust new routes for moderately ice-strengthened (Polar Class 6) ships over the North Pole, and new routes through the Northwest Passage for both vessel classes. Although numerous other nonclimatic factors also limit Arctic shipping potential, these findings have important economic, strategic, environmental, and governance implications for the region.
Lenaerts JTM, van Angelen JH, van den Broeke MR, Gardner AS, Wouters B, van Meijgaard E. Irreversible mass loss of Canadian Arctic Archipelago glaciers. Geophysical Research Letters. Irreversible mass loss of Canadian Arctic Archipelago glaciers - Lenaerts - 2013 - Geophysical Research Letters - Wiley Online Library
The Canadian Arctic Archipelago (CAA) contains the largest volume of glacier ice on Earth outside of Antarctica and Greenland. In the absence of significant calving, CAA glacier mass balance is governed by the difference between surface snow accumulation and meltwater runoff—surface mass balance. Here we use a coupled atmosphere/snow model to simulate present-day and 21st century CAA glacier surface mass balance. Through comparison with Gravity Recovery and Climate Experiment mass anomalies and in situ observations, we show that the model is capable of representing present-day CAA glacier mass loss, as well as the dynamics of the seasonal snow cover on the CAA tundra. Next, we force this model until 2100 with a moderate climate warming scenario (AR5 RCP4.5). We show that enhanced meltwater runoff from CAA glaciers is not sufficiently compensated by increased snowfall. Extrapolation of these results toward an AR5 multimodel ensemble results in sustained 21st century CAA glacier mass loss in the vast majority (>99%) of the ~7000 temperature realizations.
The Canadian Arctic Archipelago (CAA) contains the largest volume of glacier ice on Earth outside of Antarctica and Greenland. In the absence of significant calving, CAA glacier mass balance is governed by the difference between surface snow accumulation and meltwater runoff—surface mass balance. Here we use a coupled atmosphere/snow model to simulate present-day and 21st century CAA glacier surface mass balance. Through comparison with Gravity Recovery and Climate Experiment mass anomalies and in situ observations, we show that the model is capable of representing present-day CAA glacier mass loss, as well as the dynamics of the seasonal snow cover on the CAA tundra. Next, we force this model until 2100 with a moderate climate warming scenario (AR5 RCP4.5). We show that enhanced meltwater runoff from CAA glaciers is not sufficiently compensated by increased snowfall. Extrapolation of these results toward an AR5 multimodel ensemble results in sustained 21st century CAA glacier mass loss in the vast majority (>99%) of the ~7000 temperature realizations.
Scientists Find an Abrupt Warm Jog After a Very Long Cooling
Scientists Find an Abrupt Warm Jog After a Very Long Cooling - NYTimes.com
Marcott SA, Shakun JD, Clark PU, Mix AC. A Reconstruction of Regional and Global Temperature for the Past 11,300 Years. Science 2013;339(6124):1198-201. A Reconstruction of Regional and Global Temperature for the Past 11,300 Years
Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (<5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago. This cooling is largely associated with ~2°C change in the North Atlantic. Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history. Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios.
Scientists Find an Abrupt Warm Jog After a Very Long Cooling - NYTimes.com
Marcott SA, Shakun JD, Clark PU, Mix AC. A Reconstruction of Regional and Global Temperature for the Past 11,300 Years. Science 2013;339(6124):1198-201. A Reconstruction of Regional and Global Temperature for the Past 11,300 Years
Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (<5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago. This cooling is largely associated with ~2°C change in the North Atlantic. Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history. Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios.
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cvictorg
New Member
http://www.nytimes.com/2013/03/08/s...res-highest-in-4000-years-study-says.html?hpw
Global temperatures are warmer than at any time in at least 4,000 years, scientists reported Thursday, and over the coming decades are likely to surpass levels not seen on the planet since before the last ice age.
A Reconstruction of Regional and Global Temperature for the Past 11,300 Years
Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (<5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago. This cooling is largely associated with ~2°C change in the North Atlantic. Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history. Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios.
Global Average Temperatures Are Close to 11,000-Year Peak: Scientific American
The temperature trends during most of the post-ice-age period match those expected from natural factors such as the long-term variation in the tilt of Earth’s axis, says Marcott. But in the past century and a half, industrial emissions of the greenhouse gas carbon dioxide have increased — which helps to explain why global temperatures have risen so quickly in recent decades, he suggests.
Global temperatures are warmer than at any time in at least 4,000 years, scientists reported Thursday, and over the coming decades are likely to surpass levels not seen on the planet since before the last ice age.
A Reconstruction of Regional and Global Temperature for the Past 11,300 Years
Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (<5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago. This cooling is largely associated with ~2°C change in the North Atlantic. Current global temperatures of the past decade have not yet exceeded peak interglacial values but are warmer than during ~75% of the Holocene temperature history. Intergovernmental Panel on Climate Change model projections for 2100 exceed the full distribution of Holocene temperature under all plausible greenhouse gas emission scenarios.
Global Average Temperatures Are Close to 11,000-Year Peak: Scientific American
The temperature trends during most of the post-ice-age period match those expected from natural factors such as the long-term variation in the tilt of Earth’s axis, says Marcott. But in the past century and a half, industrial emissions of the greenhouse gas carbon dioxide have increased — which helps to explain why global temperatures have risen so quickly in recent decades, he suggests.
Xu L, Myneni RB, Chapin Iii FS, et al. Temperature and vegetation seasonality diminishment over northern lands. Nature Clim Change;advance online publication. http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1836.html
Global temperature is increasing, especially over northern lands (>50°?N), owing to positive feedbacks1. As this increase is most pronounced in winter, temperature seasonality (ST)—conventionally defined as the difference between summer and winter temperatures—is diminishing over time2, a phenomenon that is analogous to its equatorward decline at an annual scale. The initiation, termination and performance of vegetation photosynthetic activity are tied to threshold temperatures3. Trends in the timing of these thresholds and cumulative temperatures above them may alter vegetation productivity, or modify vegetation seasonality (SV), over time. The relationship between ST and SV is critically examined here with newly improved ground and satellite data sets. The observed diminishment of ST and SV is equivalent to 4° and 7° (5° and 6°) latitudinal shift equatorward during the past 30 years in the Arctic (boreal) region. Analysis of simulations from 17 state-of-the-art climate models4 indicates an additional STdiminishment equivalent to a 20° equatorward shift could occur this century. How SV will change in response to such large projectedST declines and the impact this will have on ecosystem services5 are not well understood. Hence the need for continued monitoring6 of northern lands as their seasonal temperature profiles evolve to resemble thosefurther south.
Global temperature is increasing, especially over northern lands (>50°?N), owing to positive feedbacks1. As this increase is most pronounced in winter, temperature seasonality (ST)—conventionally defined as the difference between summer and winter temperatures—is diminishing over time2, a phenomenon that is analogous to its equatorward decline at an annual scale. The initiation, termination and performance of vegetation photosynthetic activity are tied to threshold temperatures3. Trends in the timing of these thresholds and cumulative temperatures above them may alter vegetation productivity, or modify vegetation seasonality (SV), over time. The relationship between ST and SV is critically examined here with newly improved ground and satellite data sets. The observed diminishment of ST and SV is equivalent to 4° and 7° (5° and 6°) latitudinal shift equatorward during the past 30 years in the Arctic (boreal) region. Analysis of simulations from 17 state-of-the-art climate models4 indicates an additional STdiminishment equivalent to a 20° equatorward shift could occur this century. How SV will change in response to such large projectedST declines and the impact this will have on ecosystem services5 are not well understood. Hence the need for continued monitoring6 of northern lands as their seasonal temperature profiles evolve to resemble thosefurther south.
[ame=http://www.youtube.com/watch?v=fXS8l3_Yhh0]Climate Changes, But Facts Don't: Debunking Monckton - YouTube[/ame]
Grinsted A, Moore JC, Jevrejeva S. Projected Atlantic hurricane surge threat from rising temperatures. Proceedings of the National Academy of Sciences. http://www.pnas.org/content/early/2013/03/14/1209980110.abstract
Detection and attribution of past changes in cyclone activity are hampered by biased cyclone records due to changes in observational capabilities. Here, we relate a homogeneous record of Atlantic tropical cyclone activity based on storm surge statistics from tide gauges to changes in global temperature patterns. We examine 10 competing hypotheses using nonstationary generalized extreme value analysis with different predictors (North Atlantic Oscillation, Southern Oscillation, Pacific Decadal Oscillation, Sahel rainfall, Quasi-Biennial Oscillation, radiative forcing, Main Development Region temperatures and its anomaly, global temperatures, and gridded temperatures). We find that gridded temperatures, Main Development Region, and global average temperature explain the observations best. The most extreme events are especially sensitive to temperature changes, and we estimate a doubling of Katrina magnitude events associated with the warming over the 20th century. The increased risk depends on the spatial distribution of the temperature rise with highest sensitivity from tropical Atlantic, Central America, and the Indian Ocean. Statistically downscaling 21st century warming patterns from six climate models results in a twofold to sevenfold increase in the frequency of Katrina magnitude events for a 1 °C rise in global temperature (using BNU-ESM, BCC-CSM-1.1, CanESM2, HadGEM2-ES, INM-CM4, and NorESM1-M).
Detection and attribution of past changes in cyclone activity are hampered by biased cyclone records due to changes in observational capabilities. Here, we relate a homogeneous record of Atlantic tropical cyclone activity based on storm surge statistics from tide gauges to changes in global temperature patterns. We examine 10 competing hypotheses using nonstationary generalized extreme value analysis with different predictors (North Atlantic Oscillation, Southern Oscillation, Pacific Decadal Oscillation, Sahel rainfall, Quasi-Biennial Oscillation, radiative forcing, Main Development Region temperatures and its anomaly, global temperatures, and gridded temperatures). We find that gridded temperatures, Main Development Region, and global average temperature explain the observations best. The most extreme events are especially sensitive to temperature changes, and we estimate a doubling of Katrina magnitude events associated with the warming over the 20th century. The increased risk depends on the spatial distribution of the temperature rise with highest sensitivity from tropical Atlantic, Central America, and the Indian Ocean. Statistically downscaling 21st century warming patterns from six climate models results in a twofold to sevenfold increase in the frequency of Katrina magnitude events for a 1 °C rise in global temperature (using BNU-ESM, BCC-CSM-1.1, CanESM2, HadGEM2-ES, INM-CM4, and NorESM1-M).
Quick-Change Planet: Do Global Climate Tipping Points Exist?
An academic debate ponders whether Earth's climate could change precipitously, and how unmitigated regional stressors could irrevocably alter the planet
Quick-Change Planet: Do Global Climate Tipping Points Exist?: Scientific American
An academic debate ponders whether Earth's climate could change precipitously, and how unmitigated regional stressors could irrevocably alter the planet
Quick-Change Planet: Do Global Climate Tipping Points Exist?: Scientific American
New Models Predict Drastically Greener Arctic in Coming Decades
New models predict drastically greener Arctic in coming decades
Pearson RG, Phillips SJ, Loranty MM, et al. Shifts in Arctic vegetation and associated feedbacks under climate change. Nature Clim Change;advance online publication. http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1858.html
Climate warming has led to changes in the composition, density and distribution of Arctic vegetation in recent decades1, 2, 3, 4. These changes cause multiple opposing feedbacks between the biosphere and atmosphere5, 6, 7, 8, 9, the relative magnitudes of which will have globally significant consequences but are unknown at a pan-Arctic scale10. The precise nature of Arctic vegetation change under future warming will strongly influence climate feedbacks, yet Earth system modelling studies have so far assumed arbitrary increases in shrubs (for example, +20%; refs 6, 11), highlighting the need for predictions of future vegetation distribution shifts. Here we show, using climate scenarios for the 2050s and models that utilize statistical associations between vegetation and climate, the potential for extremely widespread redistribution of vegetation across the Arctic. We predict that at least half of vegetated areas will shift to a different physiognomic class, and woody cover will increase by as much as 52%. By incorporating observed relationships between vegetation and albedo, evapotranspiration and biomass, we show that vegetation distribution shifts will result in an overall positive feedback to climate that is likely to cause greater warming than has previously been predicted. Such extensive changes to Arctic vegetation will have implications for climate, wildlife and ecosystem services.
New models predict drastically greener Arctic in coming decades
Pearson RG, Phillips SJ, Loranty MM, et al. Shifts in Arctic vegetation and associated feedbacks under climate change. Nature Clim Change;advance online publication. http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1858.html
Climate warming has led to changes in the composition, density and distribution of Arctic vegetation in recent decades1, 2, 3, 4. These changes cause multiple opposing feedbacks between the biosphere and atmosphere5, 6, 7, 8, 9, the relative magnitudes of which will have globally significant consequences but are unknown at a pan-Arctic scale10. The precise nature of Arctic vegetation change under future warming will strongly influence climate feedbacks, yet Earth system modelling studies have so far assumed arbitrary increases in shrubs (for example, +20%; refs 6, 11), highlighting the need for predictions of future vegetation distribution shifts. Here we show, using climate scenarios for the 2050s and models that utilize statistical associations between vegetation and climate, the potential for extremely widespread redistribution of vegetation across the Arctic. We predict that at least half of vegetated areas will shift to a different physiognomic class, and woody cover will increase by as much as 52%. By incorporating observed relationships between vegetation and albedo, evapotranspiration and biomass, we show that vegetation distribution shifts will result in an overall positive feedback to climate that is likely to cause greater warming than has previously been predicted. Such extensive changes to Arctic vegetation will have implications for climate, wildlife and ecosystem services.
The End of an Illusion
Money quote:
Read the whole thing. It's all coming down. Just like ObamaCare.
The world is starting to make more sense now. Hopefully this is a trend and reason will continue to replace the herd mentality.
Money quote:
Read the whole thing. It's all coming down. Just like ObamaCare.
The world is starting to make more sense now. Hopefully this is a trend and reason will continue to replace the herd mentality.
Last edited by a moderator:
Thompson LG, Mosley-Thompson E, Davis ME, et al. Annually Resolved Ice Core Records of Tropical Climate Variability Over the Past ~1800 Years. Science. Annually Resolved Ice Core Records of Tropical Climate Variability Over the Past ~1800 Years
Ice cores from low latitudes can provide a wealth of unique information about past climate in the tropics, but they are difficult to recover and few exist. Here, we report annually resolved ice core records from the Quelccaya ice cap (5670 masl) in Peru which extend back ~1800 years and provide a high-resolution record of climate variability there. Oxygen isotopic ratios (?18O) are linked to sea-surface temperatures in the tropical eastern Pacific, while concentrations of ammonium and nitrate document the dominant role played by the migration of the Intertropical Convergence Zone in the region of the tropical Andes. Quelccaya continues to retreat and thin: Radiocarbon dates on wetland plants exposed along its retreating margins indicate it has not been smaller for at least six millennia.
In Sign of Warming, 1,600 Years of Ice in Andes Melted in 25 Years
http://www.nytimes.com/2013/04/05/w...s-melted-in-25-years-scientists-say.html?_r=0
Ice cores from low latitudes can provide a wealth of unique information about past climate in the tropics, but they are difficult to recover and few exist. Here, we report annually resolved ice core records from the Quelccaya ice cap (5670 masl) in Peru which extend back ~1800 years and provide a high-resolution record of climate variability there. Oxygen isotopic ratios (?18O) are linked to sea-surface temperatures in the tropical eastern Pacific, while concentrations of ammonium and nitrate document the dominant role played by the migration of the Intertropical Convergence Zone in the region of the tropical Andes. Quelccaya continues to retreat and thin: Radiocarbon dates on wetland plants exposed along its retreating margins indicate it has not been smaller for at least six millennia.
In Sign of Warming, 1,600 Years of Ice in Andes Melted in 25 Years
http://www.nytimes.com/2013/04/05/w...s-melted-in-25-years-scientists-say.html?_r=0
cvictorg
New Member
http://www.nytimes.com/video/2013/04/05/business/100000002112739/drought-on-the-range.html
The United States cattle herd is at its lowest level in 60 years, largely because of the drought. Many ranchers are struggling to hang on.
The United States cattle herd is at its lowest level in 60 years, largely because of the drought. Many ranchers are struggling to hang on.
Cherrypicking to Deny Continued Ocean and Global Warming
Cherrypicking to Deny Continued Ocean and Global Warming
Cherrypicking to Deny Continued Ocean and Global Warming
cvictorg
New Member
Dr. Jeff Masters: Katrina-level storm surges have more than doubled due to global warming – A Few Things Ill Considered
The Future Holds Ten Times More Hurricane Surges, Finds Research
By examining the frequency of extreme storm surges in the past, previous research has shown that there was an increasing tendency for storm hurricane surges when the climate was warmer. But how much worse will it get as temperatures rise in the future? How many extreme storm surges like that from Hurricane Katrina, which hit the US coast in 2005, will there be as a result of global warming? New research from the Niels Bohr Institute shows that there will be a tenfold increase in frequency if the climate becomes two degrees Celcius warmer.
Since 1923, there has been a 'Katrina' magnitude storm surge every 20 years.
"We find that 0.4 degrees Celcius warming of the climate corresponds to a doubling of the frequency of extreme storm surges like the one following Hurricane Katrina. With the global warming we have had during the 20th century, we have already crossed the threshold where more than half of all 'Katrinas' are due to global warming," explains Aslak Grinsted.
"If the temperature rises an additional degree, the frequency will increase by 3-4 times and if the global climate becomes two degrees warmer, there will be about 10 times as many extreme storm surges. This means that there will be a 'Katrina' magnitude storm surge every other year," says Aslak Grinsted and he points out that in addition to there being more extreme storm surges, the sea will also rise due to global warming. As a result, the storm surges will become worse and potentially more destructive.
The Future Holds Ten Times More Hurricane Surges, Finds Research
By examining the frequency of extreme storm surges in the past, previous research has shown that there was an increasing tendency for storm hurricane surges when the climate was warmer. But how much worse will it get as temperatures rise in the future? How many extreme storm surges like that from Hurricane Katrina, which hit the US coast in 2005, will there be as a result of global warming? New research from the Niels Bohr Institute shows that there will be a tenfold increase in frequency if the climate becomes two degrees Celcius warmer.
Since 1923, there has been a 'Katrina' magnitude storm surge every 20 years.
"We find that 0.4 degrees Celcius warming of the climate corresponds to a doubling of the frequency of extreme storm surges like the one following Hurricane Katrina. With the global warming we have had during the 20th century, we have already crossed the threshold where more than half of all 'Katrinas' are due to global warming," explains Aslak Grinsted.
"If the temperature rises an additional degree, the frequency will increase by 3-4 times and if the global climate becomes two degrees warmer, there will be about 10 times as many extreme storm surges. This means that there will be a 'Katrina' magnitude storm surge every other year," says Aslak Grinsted and he points out that in addition to there being more extreme storm surges, the sea will also rise due to global warming. As a result, the storm surges will become worse and potentially more destructive.
Guemas V, Doblas-Reyes FJ, Andreu-Burillo I, Asif M. Retrospective prediction of the global warming slowdown in the past decade. Nature Clim Change;advance online publication. http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1863.html
Despite a sustained production of anthropogenic greenhouse gases, the Earth’s mean near-surface temperature paused its rise during the 2000–2010 period1. To explain such a pause, an increase in ocean heat uptake below the superficial ocean layer2, 3 has been proposed to overcompensate for the Earth’s heat storage. Contributions have also been suggested from the deep prolonged solar minimum4, the stratospheric water vapour5, the stratospheric6 and tropospheric aerosols7. However, a robust attribution of this warming slowdown has not been achievable up to now. Here we show successful retrospective predictions of this warming slowdown up to 5 years ahead, the analysis of which allows us to attribute the onset of this slowdown to an increase in ocean heat uptake. Sensitivity experiments accounting only for the external radiative forcings do not reproduce the slowdown. The top-of-atmosphere net energy input remained in the [0.5–1]?W?m?2 interval during the past decade, which is successfully captured by our predictions. Most of this excess energy was absorbed in the top 700?m of the ocean at the onset of the warming pause, 65% of it in the tropical Pacific and Atlantic oceans. Our results hence point at the key role of the ocean heat uptake in the recent warming slowdown. The ability to predict retrospectively this slowdown not only strengthens our confidence in the robustness of our climate models, but also enhances the socio-economic relevance of operational decadal climate predictions.
Despite a sustained production of anthropogenic greenhouse gases, the Earth’s mean near-surface temperature paused its rise during the 2000–2010 period1. To explain such a pause, an increase in ocean heat uptake below the superficial ocean layer2, 3 has been proposed to overcompensate for the Earth’s heat storage. Contributions have also been suggested from the deep prolonged solar minimum4, the stratospheric water vapour5, the stratospheric6 and tropospheric aerosols7. However, a robust attribution of this warming slowdown has not been achievable up to now. Here we show successful retrospective predictions of this warming slowdown up to 5 years ahead, the analysis of which allows us to attribute the onset of this slowdown to an increase in ocean heat uptake. Sensitivity experiments accounting only for the external radiative forcings do not reproduce the slowdown. The top-of-atmosphere net energy input remained in the [0.5–1]?W?m?2 interval during the past decade, which is successfully captured by our predictions. Most of this excess energy was absorbed in the top 700?m of the ocean at the onset of the warming pause, 65% of it in the tropical Pacific and Atlantic oceans. Our results hence point at the key role of the ocean heat uptake in the recent warming slowdown. The ability to predict retrospectively this slowdown not only strengthens our confidence in the robustness of our climate models, but also enhances the socio-economic relevance of operational decadal climate predictions.
Ah, it begins. Reality is finally setting in. Thank God for that. Climate alarmists predictions are not coming true and have never come true, and now that the temperature data is showing no raise at all and the hockey stick figure has been discredited, sense is starting to take over.
[ame=http://www.youtube.com/watch?feature=player_embedded&v=6VtdfSnK0BM]Rich Lowry Discusses 'The New Climate Deniers - YouTube[/ame]
So the AGW crowd can continue the mental masturbation all by themselves now, tucked away in the privacy of their own homes, or perhaps even a few groups could get together for a reach around party. Nothing is going to be done about something that does not exist. So give your hands a break...and your brains.
[ame=http://www.youtube.com/watch?feature=player_embedded&v=6VtdfSnK0BM]Rich Lowry Discusses 'The New Climate Deniers - YouTube[/ame]
So the AGW crowd can continue the mental masturbation all by themselves now, tucked away in the privacy of their own homes, or perhaps even a few groups could get together for a reach around party. Nothing is going to be done about something that does not exist. So give your hands a break...and your brains.
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