The more extreme the heat wave, the more likely it is due to the change in the climate.
Though the report still says, rightly, that any specific weather event can not be solely tied to climate change — be it the totally unseasonable snowfall that hit the Northeast this past weekend, the devastating flooding in Thailand, etc. — but that scientists now are 99 % certain that climate change will cause
more extreme heat waves, fewer extreme spells of cold weather, and more intense downpours.
And cities everywhere face risks including more frequent and
more extreme heat waves and increasing heavy downpours.
Not exact matches
This means that the science of climate change may partially undergo a shift of its own, moving from trying to prove it is a problem (it is now «very likely» that greenhouse gases in the atmosphere have already caused enough warming to trigger stronger droughts,
heat waves,
more and bigger forest fires and
more extreme storms and flooding) to figuring out ways to fix it.
The climate, of course, continues to vary around the increased averages, and
extremes have changed consistently with these averages — frost days and cold days and nights have become less common, while
heat waves and warm days and nights have become
more common.
«Global warming boosts the probability of really
extreme events, like the recent US
heat wave, far
more than it boosts
more moderate events,» point out climate scientists Stefan Rahmstorf and Dim Coumou in a blogpost on RealClimate.org.
Increased fluctuations in the path of the North Atlantic jet stream since the 1960s coincide with
more extreme weather events in Europe such as
heat waves, droughts, wildfires and flooding, reports a University of Arizona - led team.
Public health will suffer as
heat waves become
more frequent and intense, rising seas inundate coastal cities,
extreme storms lead to
more deaths and catastrophic wildfires burn
more forests and reduce air quality.
«Dangerous» global warming includes consequences such as increased risk of
extreme weather and climate events ranging from
more intense
heat waves, hurricanes, and floods, to prolonged droughts.
In the absence of efforts to curtail those emissions, should we expect
more heat waves and other
extreme weather this summer?
As average U.S. temperatures warm between 3 °F and
more than 9 °F by the end of the century, depending on how greenhouse gas emissions are curtailed or not in the coming years, the
waves of
extreme heat the country is likely to experience could bend and buckle rails into what experts call «sun kinks.»
NCAR, which is financed in part by the National Science Foundation, has spent several years searching for ways to extend the predicability of floods, droughts,
heat waves and other
extreme weather events from weeks to months as a way to give weather - sensitive sectors such as agriculture
more time to protect themselves against costly losses.
But unless such drastic action is taken in the next few years, we are headed for a very different world, one in which seas will rise by
more than 5 metres over the coming centuries, and droughts, floods and
extreme heat waves will ravage many parts of the world (see «Rising seas expected to sink islands near US capital in 50 years «-RRB-.
There's also evidence that as it wobbles, it can get stuck out of kilter, which can lead to
more persistent weather
extremes, including
heat waves, cold snaps, droughts and flooding.
That
extreme heat could lead to
more deadly
heat waves, wildfires and other climate - related disasters.
Across the globe in recent decades, there has been an increase in the number of hot
extremes, particularly very warm nights.1 Hot days have also been hotter and
more frequent.2 Since 1950 the number of
heat waves has increased and
heat waves have become longer.3
From
heat waves to downpours, a number of
extreme weather phenomena have become
more common or severe due to climate change.
Scorching summertime
heat waves in Europe, Asia and North America, as well as
extreme cold snaps in central Asia, have become
more likely because of changes in the way air is flowing over those regions, a new study detailed in the journal Nature suggests.
While natural variability continues to play a key role in
extreme weather, climate change has shifted the odds and changed the natural limits, making
heat waves more frequent and
more intense.
In this case, the scientists looked at how much
more likely the
extreme temperatures recorded across Europe were during this
heat wave because of warming, and found clear indications that it upped the odds.
So in this sense, the 2002 drought and associated
heat waves were
more extreme than the earlier droughts, because the impact of the low rainfall was exacerbated by high potential evaporation (Karoly et al., 2003; Nicholls, 2004).
More deaths from
heat waves can be modelled just as well as fewer deaths from
extreme cold.
When discussing
extreme weather and climate, tornadoes should not be conflated with the other
extreme weather events for which the connection is considerably
more straightforward and better documented, including deluges, droughts, and
heat waves.
I've shown before that the typical European winter gets far
more weather - attributed deaths than the
extreme heat wave of 2003, so it only stands to reason that GW is saving far
more lives in Europe than it is taking, right?
As to climate change and its impacts on storms and floods, the IPCC and NOAA among many other top scientific groups have indicated that climate change will result in
more extreme weather events, including
heat waves, wildfires, storms and floods.
Are the
heat waves really getting
more extreme?
The first thorough federal review of research on how global warming may affect
extreme climate events in North America forecasts
more drenching rains, parching droughts (especially in the Southwest), intense
heat waves and stronger hurricanes if long - lived greenhouse gases continue building in the atmosphere.
Warming over land can have multiple effects, including melting of mountain glaciers, spread of deserts in continental interiors, greater flooding,
more frequent
heat waves and other
extreme weather patterns.
In the Northeast, «Communities are affected by
heat waves,
more extreme precipitation events, and coastal flooding due to sea level rise and storm surge,» for example, while in the Southeast and Caribbean, «Decreased water availability, exacerbated by population growth and land - use change, causes increased competition for water.
Some assessments still rely on simple reasoning about how
extremes might be expected to change with global warming (e.g., warming could be expected to lead to
more heat waves).
Our warming world is, according to the United Nations Intergovernmental Panel on Climate Change, increasing
heat waves and intense precipitation in some places, and is likely to bring
more extreme weather in the future.
The role of climate change in causing
extreme heat waves, drastic rainfall, negative impacts on human health and threatened food security have received
more attention recently than megadrought.
The effects of temperature
extremes on human health have been well documented for increased
heat waves, 46,47,48,49 which cause
more deaths, 50,51 hospital admissions52, 53,54 and population vulnerability.55, 56
Projections suggest an increase in
extreme weather events, such as heavy rainfall,
more intense storms and
heat -
waves.
Observational data, evidence from field experiments, and quantitative modeling are the evidence base of the negative effects of
extreme weather events on crop yield: early spring
heat waves followed by normal frost events have been shown to decimate Midwest fruit crops;
heat waves during flowering, pollination, and grain filling have been shown to significantly reduce corn and wheat yields;
more variable and intense spring rainfall has delayed spring planting in some years and can be expected to increase erosion and runoff; and floods have led to crop losses.4, 5,6,7
It finds many significant climate and development impacts are already being felt in some regions, and in some cases multiple threats of increasing
extreme heat waves, sea level rise,
more severe storms, droughts and floods are expected to have further severe negative implications for the poorest.
Heat waves, droughts, wildfires, heavy downpours, floods, and other
extreme weather events are projected to become
more frequent and intense, with serious consequences for human health and well - being.
Northeast states can expect
more climate change related
heat waves — with significantly
more days above 90 degrees F — and flooding from sea level rise and
extreme precipitation events.
As reported by Chris Mooney at Mother Jones at the time (now a journalist at the Washington Post), the draft report warned unequivocally that unchecked greenhouse gas emissions would cause the global warming trend to «accelerate significantly,» bringing
more heat waves and weather
extremes, severe storms, rising seas, devastating floods, prolonged droughts, and
more.
Evidence suggests that Arctic warming is causing weather patterns to become
more persistent, which can lead to
extremes such as droughts, cold spells,
heat waves, and some flooding events.
For the United States, observations clearly show a declining frequency of
extreme weather events, that sea level changes are indistinguishable from geological uplift or sinking processes, and decreased risk of regional water scarcity (due to
more frequent winter polar vortices replenishing the water table),
heat waves, wildfires, and the disturbance of biological systems.
For example, in IPCC (2007, Fourth Assessment Report — AR4; Summary for policymakers, p. 15), we read (our emphasis): «It is very likely that hot
extremes,
heat waves and heavy precipitation events will continue to become
more frequent».
Communities around the world are feeling these impacts in the form of
extreme weather, record drought,
heat waves, floods and
more.
While the 2003
heat wave was unusual in today's climate, 23 Europe is highly likely to face even hotter summers
more often in coming decades.24 Scientists estimate that human activities have already at least doubled the risk of an
extreme heat wave.25
The U.S. National Climate Assessment shows that summers are getting hotter,
heat waves are lasting longer, and weather is getting
more extreme.
Like Hansen et al., Donat and Alexander (2012) found that global warming has made
extreme heat waves more likely to occur.
Ironically, people in cold regions can be most vulnerable to
heat waves, because they are not acclimated to extremely hot weather, and because buildings designed for cold climates may not offer protection against
extreme heat and high humidity.32 The elderly and those who do not have access to air - conditioning will likely be less resilient in the face of
more frequent
heat waves.19
Stronger and longer
heat waves,
more frequent
extreme weather events such as flooding and tropical cyclones, rises in sea level, and increased air pollution will become
more the rule than the exception.
The report's executive summary declares that U.S.
heat waves have become
more common since the mid-1960s, although acknowledging the 1930s Dust Bowl as the peak period for
extreme heat.
Much ado has been made recently in the media and the blogosphere of recent
extreme weather events around the world: the flooding in Tennessee and Pakistan, the Moscow
heat waves, record drought in the Amazon, and yet
more flooding in Queensland and Brazil.