Lethal Heating: 11/18/15

NASA

The potential future effects of global climate change include more frequent wildfires, longer periods of drought in some regions and an increase in the number, duration and intensity of tropical storms. Credit: Left - Mellimage/Shutterstock.com, center - Montree Hanlue/Shutterstock.com.

Global climate change has already had observable effects on the environment. Glaciers have shrunk, ice on rivers and lakes is breaking up earlier, plant and animal ranges have shifted and trees are flowering sooner.

Effects that scientists had predicted in the past would result from global climate change are now occurring: loss of sea ice, accelerated sea level rise and longer, more intense heat waves.
Taken as a whole, the range of published evidence indicates that the net damage costs of climate change are likely to be significant and to increase over time.

- Intergovernmental Panel on Climate Change

Scientists have high confidence that global temperatures will continue to rise for decades to come, largely due to greenhouse gases produced by human activities. The Intergovernmental Panel on Climate Change (IPCC), which includes more than 1,300 scientists from the United States and other countries, forecasts a temperature rise of 2.5 to 10 degrees Fahrenheit over the next century.
According to the IPCC, the extent of climate change effects on individual regions will vary over time and with the ability of different societal and environmental systems to mitigate or adapt to change.
The IPCC predicts that increases in global mean temperature of less than 1.8 to 5.4 degrees Fahrenheit (1 to 3 degrees Celsius) above 1990 levels will produce beneficial impacts in some regions and harmful ones in others. Net annual costs will increase over time as global temperatures increase.
"Taken as a whole," the IPCC states, "the range of published evidence indicates that the net damage costs of climate change are likely to be significant and to increase over time."

Future effects
Some of the long-term effects of global climate change in the United States are as follows, according to the Third National Climate Assessment Report:

Change will continue through this century and beyond
Global climate is projected to continue to change over this century and beyond. The magnitude of climate change beyond the next few decades depends primarily on the amount of heat-trapping gases emitted globally, and how sensitive the Earth’s climate is to those emissions.

Earth’s vital signs: Sea level
An indicator of current global sea level as measured by satellites; updated monthly.

GISS climate models
NASA visualizations of future precipitation scenarios.

Climate Time Machine
Go backward and forward in time with this interactive visualization that illustrates how the Earth's climate has changed in recent history.

Temperatures will continue to rise
Because human-induced warming is superimposed on a naturally varying climate, the temperature rise has not been, and will not be, uniform or smooth across the country or over time.

Video: Global warming from 1880 to 2013
A visualization of global temperature changes since 1880 based on NASA GISS data.

21st century temperature scenarios
NASA visualization of future global temperature projections based on current climate models

Frost-free season (and growing season) will lengthen

The length of the frost-free season (and the corresponding growing season) has been increasing nationally since the 1980s, with the largest increases occurring in the western United States, affecting ecosystems and agriculture. Across the United States, the growing season is projected to continue to lengthen.
In a future in which heat-trapping gas emissions continue to grow, increases of a month or more in the lengths of the frost-free and growing seasons are projected across most of the U.S. by the end of the century, with slightly smaller increases in the northern Great Plains. The largest increases in the frost-free season (more than eight weeks) are projected for the western U.S., particularly in high elevation and coastal areas. The increases will be considerably smaller if heat-trapping gas emissions are reduced.

Visualization comparing 1950s and 1920s
This NASA visualization presents observational evidence that the growing season (climatological spring) is occurring earlier in the Northern Hemisphere.

Changes in precipitation patterns

Average U.S. precipitation has increased since 1900, but some areas have had increases greater than the national average, and some areas have had decreases. More winter and spring precipitation is projected for the northern United States, and less for the Southwest, over this century. Projections of future climate over the U.S. suggest that the recent trend towards increased heavy precipitation events will continue. This trend is projected to occur even in regions where total precipitation is expected to decrease, such as the Southwest.

NASA visualizations of future precipitation scenarios
These NASA visualizations show model projections of the precipitation changes from 2000 to 2100 as a percentage difference between the 30-year precipitation averages and the 1970-1999 average.

Precipitation Measurement Missions
The official website for NASA's fleet of Earth science missions that study rainfall and other types precipitation around the globe.

Precipitation quiz
Earth’s water is stored in ice and snow, lakes and rivers, the atmosphere and the oceans. How much do you know about Earth's water cycle and the crucial role it plays in our climate?

More droughts and heat waves
Droughts in the Southwest and heat waves (periods of abnormally hot weather lasting days to weeks) everywhere are projected to become more intense, and cold waves less intense everywhere.
Summer temperatures are projected to continue rising, and a reduction of soil moisture, which exacerbates heat waves, is projected for much of the western and central U.S. in summer.
By the end of this century, what have been once-in-20-year extreme heat days (one-day events) are projected to occur every two or three years over most of the nation.

NASA: Megadroughts in U.S. West projected to be worst of millennium

Droughts in the Southwest and Central Plains of the United States in the second half of the 21st century could be drier and longer than anything humans have seen in those regions in the last 1,000 years, according to a NASA study published in Science Advances on February 12, 2015.

Hurricanes will become stronger and more intense

The intensity, frequency and duration of North Atlantic hurricanes, as well as the frequency of the strongest (Category 4 and 5) hurricanes, have all increased since the early 1980s. The relative contributions of human and natural causes to these increases are still uncertain. Hurricane-associated storm intensity and rainfall rates are projected to increase as the climate continues to warm.

NASA: What are the chances of another Hurricane Katrina?

According to a new NASA study, a string of nine years without a major hurricane landfall in the U.S. is Iikely to come along only once every 177 years. This video explains the findings of this study.

Sea level will rise 1-4 feet by 2100
Global sea level has risen by about 8 inches since reliable record keeping began in 1880. It is projected to rise another 1 to 4 feet by 2100. This is the result of added water from melting land ice and the expansion of seawater as it warms.
In the next several decades, storm surges and high tides could combine with sea level rise and land subsidence to further increase flooding in many of these regions. Sea level rise will not stop in 2100 because the oceans take a very long time to respond to warmer conditions at the Earth’s surface. Ocean waters will therefore continue to warm and sea level will continue to rise for many centuries at rates equal to or higher than that of the current century.

Earth’s vital signs: Sea level
An indicator of current global sea level as measured by satellites; updated monthly.

Sea level quiz
Test your knowledge of sea level rise and its effect on global populations.

Arctic likely to become ice-free
The Arctic Ocean is expected to become essentially ice free in summer before mid-century.

Earth’s vital signs: Sea ice
An indicator of changes in the Arctic sea ice minimum over time. Arctic sea ice extent both affects and is affected by global climate change.

Global Ice Viewer
An interactive exploration of how global warming is affecting sea ice, glaciers and continental ice sheets worldwide.

Washington Post - Jason Samenow

As of today, the warm ocean temperatures that define El Niño have surged to a stunning three degrees Celsius (5.4 degrees Fahrenheit) warmer than normal in the central tropical Pacific, the highest level ever measured.

Anomaly for El NIño 3.4 region spikes at record +3.0

Many global impacts already
El Niño events, while simply descriptions of ocean temperatures in the tropical Pacific and not storms, have ripple effects on weather patterns all over the world.
“Severe droughts and devastating flooding being experienced throughout the tropics and sub-tropical zones bear the hallmarks of this El Niño, which is the strongest for more than 15 years,” said World Meteorological Organization (WMO) Secretary-General Michel Jarraud in a news release.

According to the World Meteorological Organization, the El Niño of 2015-2016 is shaping up to be one of the strongest in this past century. Here are the types of weather we can expect around the world due to this year's El Niño. (World Meteorological Organization/ YouTube)

The WMO published a long list of many harmful weather impacts for which this El Niño has been implicated, including coral bleaching and the most active season for intense tropical cyclones in the Northern Hemisphere on record, both due to historically warm ocean waters.
[The Northern Hemisphere’s record-shattering tropical cyclone season, by the numbers]
It also linked El Niño with drought in South East, Asia which has lead to one of the worst wildfire outbreaks in Indonesia on record.
[Indonesian fires are pouring huge amounts of carbon into the atmosphere]
Not all impacts from El Niño have been harmful. For example, it introduced wind shear in the tropical Atlantic which has depressed hurricane activity that might impact North America and may already be increasing precipitation in California, which is suffering from a historic drought.
[Is the near-record El Niño already chipping away at the California, western drought?]

‘Uncharted territory’
This El Niño is operating in a warmer world in which forecasters have no prior experience predicting its effects.
“This event is playing out in uncharted territory,” Jarraud said. “Our planet has altered dramatically because of climate change, the general trend towards a warmer global ocean, the loss of Arctic sea ice and of over a million square kilometers of summer snow cover in the northern hemisphere.”
“So this naturally occurring El Niño event and human induced climate change may interact and modify each other in ways which we have never before experienced,” he said.
“Even before the onset of El Niño, global average surface temperatures had reached new records. El Niño is turning up the heat even further,” Jarraud added.
While El Niño has certain characteristic effects which we have discussed at length in the past (for the D.C. area, and the U.S. and beyond), the background warmth adds a potential element of surprise heading into the winter months.

Comparing this year’s El Niño vs. 1997-1998, and what it portends
While today’s unsurpassed ocean temperature measurement in the central tropical Pacific made history, it is too soon to know if this toasty temperature reading is just a blip or a signal. In order for this El Niño to officially pass 1997-1998’s event as the strongest on record, the warm waters would need to be sustained near these level for three months.

3.0C in Nino 3.4 using OISSTv2 is the highest on record.

“A week of sea surface temperature-only data isn’t enough to say this is a record,” said NOAA climate analyst Michelle L’Heureux in an email.
Forecasters expect strong El Niño levels to persist through the winter, but it may be peaking now and about to begin a gradual decay. However, the event’s recent and projected intensity may be enough for this event to surpass 1997-1998.
“Judging from the trajectory of SST anomalies … it is likely that one of the late-year three-month average … sea surface temperature values in 2015 will end up upending 1997’s record warmth and claim for the 2015 the title as strongest El Niño event on record,” wrote Weather Underground meteorologist Jeff Masters.
Every El Niño has its own signature and, so far, what sets this one apart is the amount of warm water it has generated across a vast expanse of the Pacific – spanning both the eastern and central part of the ocean basin. While it hasn’t been as intense in the eastern tropical Pacific as 1997-1998, its warm waters have extended farther west.

Compare and contrast: Weekly SST anomalies for this week in 1982, 1997, and 2015.

“So, in terms of the eastern Pacific, this event is weaker than 1997, but in terms of the central Pacific, the present event is stronger,” said Paul Roundy, a professor of atmospheric science at the University of Albany.
Phil Klotzbach, a tropical weather researcher from Colorado State University, says a powerful eastward push of water known as a Kelvin wave may lead to some warming in the eastern Pacific over the next few weeks.
The implications of warm water covering such a vast area of the Pacific in terms of weather patterns in the U.S. are unclear.
Sometimes El Niño events which have their warmest waters in the central rather than eastern Pacific favor less precipitation in California and colder conditions in the Northeast U.S. than events with warmer water to the east. But researchers aren’t convinced this event will behave like a central Pacific El Niño, sometimes described as a Modoki event.
“Although it has large sea surface temperature anomalies across the central basin, it is NOT a central Pacific El Niño event,” Roundy said. “The present circulation response pattern and model forecasts agree that circulation outcomes are likely to be more like strong east Pacific events, because convection is aligned well east of the dateline.”
Klotzbach along with two climate researchers at NOAA’s Climate Prediction Center, Jon Gottschalck and Stephen Baxter, said they agreed with Roundy’s view via email.
Jason Furtado, a professor of meteorology at the University of Oklahoma, said while he concurred this El Niño is not a central Pacific event, the very warm waters observed there might mean the winter bears some of its characteristics. Furtado also cautioned El Niño “is but one ingredient for our winter climate – its interactions with other processes and climate patterns will also be important to monitor.”

18/11/2015

The Consequences Of Climate Change

By One Measure, This Wicked El Niño Is The Strongest Ever Recorded: What It Means