The argument against this should be obvious, such a small group may be non-representative
of regional temperature changes, and instead reflective of other environmental factors that impacted the individual trees and groups of trees.
Joint attribution involves attribution of significant changes in a natural or managed system to regional temperature changes, and attribution of a significant fraction
of the regional temperature change to human activities.
Not exact matches
This is a strong indication that agriculture, and not
changing sea surface
temperature, caused the
regional changes in climate during the last third
of the 20th century, the researchers say.
The model explicitly accounts for the effects
of temperature and soil moisture
changes (positive and negative) on global and
regional wheat production fluctuations.
Determining the rate
of temperature change is more difficult at a local and
regional level because researchers have less data to average, so trends are not as evident because
of «statistical noise.»
Those models will look at impacts such as
regional average
temperature change, sea - level rise, ocean acidification, and the sustainability
of soils and water as well as the impacts
of invasive species on food production and human health.
New research published this week in the Journal
of Climate reveals that one key measurement — large - scale upper - ocean
temperature changes caused by natural cycles
of the ocean — is a good indicator
of regional coastal sea level
changes on these decadal timescales.
Forcing
changes of similar magnitude, due to water vapour variations, are measurable as
regional temperature changes in Europe, see Philipona, but aerosol
changes are not...
Efforts to reform the single - sector approach to marine spatial management should incorporate expected climate - induced
changes in
temperature, oxygenation, pH, and POC flux to the seabed in the development
of regional and international management scenarios.
Additionally, there were also
regional differences in the spatial patterns
of change trend in the ARNC
temperature at a given time.
Based on
regional studies, the Intergovernmental Panel on Climate
Change (IPCC) estimated that 20 — 30 % of the world's species are likely to be at increasingly high risk of extinction from climate change impacts within this century if global mean temperatures exceed 2 — 3 °C above pre-industrial levels [6], while Thomas et al. [5] predicted that 15 — 37 % of species could be «committed to extinction» due to climate change by
Change (IPCC) estimated that 20 — 30 %
of the world's species are likely to be at increasingly high risk
of extinction from climate
change impacts within this century if global mean temperatures exceed 2 — 3 °C above pre-industrial levels [6], while Thomas et al. [5] predicted that 15 — 37 % of species could be «committed to extinction» due to climate change by
change impacts within this century if global mean
temperatures exceed 2 — 3 °C above pre-industrial levels [6], while Thomas et al. [5] predicted that 15 — 37 %
of species could be «committed to extinction» due to climate
change by
change by 2050.
At 1.5 / 2 °C
temperature warming level, how the global and
regional climate will
change, is a matter
of public concern and relates to the decisions
of policies, guidelines and measures on mitigation and adaption
of future climate
change.
Human induced trend has two components, namely (a) greenhouse effect [this includes global and local /
regional component] and (b) non-greenhouse effect [local /
regional component]-- according to IPCC (a) is more than half
of global average
temperature anomaly wherein it also includes component
of volcanic activities, etc that comes under greenhouse effect; and (b) contribution is less than half — ecological
changes component but this is biased positive side by urban - heat - island effect component as the met network are concentrated in urban areas and rural - cold - island effect is biased negative side as the met stations are sparsely distributed though rural area is more than double to urban area.
However, there are various other plausible explanations, for example: —
changes in US
temperatures since the 1930s / 1940s show
regional variation within the overall warming trend at those latitudes; — actually I'm struggling to think
of any others, apart from inaccuracies in the US
temperature record but these have tended to point the other way.
What really concerns me is that I've read a lot about climate models not being able to replicate the magnitude
of abrupt
regional temperature changes in the past, and Raypierre has said here that he fears that past climate records point towards some yet unknown positive feedback which might amplify warming at the northern latitudes.
Neglecting the significance
of the large
regional differences in past
temperature changes is another classic pitfall in the arguments put forward by many climate
change contrarians (see Myth # 2 here).
The attribution
of the term at
regional scales is complicated by significant
regional variations in
temperature changes due to the the influence
of modes
of climate variability such as the North Atlantic Oscillation and the El Nino / Southern Oscillation.
At the hemispheric - mean scale, the «Little Ice Age» is only a moderate cooling because larger offsetting
regional patterns
of temperature change (both warm and cold) tend to cancel in a hemispheric or global mean.
The new research is a
regional climate study
of historical sea level pressures, winds and
temperatures over the eastern Pacific Ocean and draws no conclusions about climate
change on a global scale.
A comprehensive new analysis
of temperature changes over the continents through 2,000 years has found that a long slide in
temperatures in most regions preceded the unusual global warming
of recent decades, but with a lot
of regional variability and other fascinating details.
Global climate
change risks are high to very high with global mean
temperature increase
of 4 °C or more above preindustrial levels in all reasons for concern (Assessment Box SPM.1), and include severe and widespread impacts on unique and threatened systems, substantial species extinction, large risks to global and
regional food security, and the combination
of high
temperature and humidity compromising normal human activities, including growing food or working outdoors in some areas for parts
of the year (high confidence).
The climate
change in this period is generally believed to be associated with precessional
changes in the distribution
of solar radiation, which primarily affect land - sea
temperature contrast, and give only a
regional warming, plus an enhancement
of certain monsoonal circulations.
[Response: Despite the evidence for rapid
regional climate
changes during certain past transitional periods (e.g. the Younger Dryas), there is no evidence that global mean
temperature changes of the amplitude seen in the past century have occured on centennial or shorter timescales in the past.
-- Projected precipitation and
temperature changes imply
changes in floods, although overall there is low confidence at the global scale regarding climate - driven
changes in magnitude or frequency
of river - related flooding, due to limited evidence and because the causes
of regional changes are complex.
Re 9 wili — I know
of a paper suggesting, as I recall, that enhanced «backradiation» (downward radiation reaching the surface emitted by the air / clouds) contributed more to Arctic amplification specifically in the cold part
of the year (just to be clear, backradiation should generally increase with any warming (aside from greenhouse feedbacks) and more so with a warming due to an increase in the greenhouse effect (including feedbacks like water vapor and, if positive, clouds, though
regional changes in water vapor and clouds can go against the global trend); otherwise it was always my understanding that the albedo feedback was key (while sea ice decreases so far have been more a summer phenomenon (when it would be warmer to begin with), the heat capacity
of the sea prevents much
temperature response, but there is a greater build up
of heat from the albedo feedback, and this is released in the cold part
of the year when ice forms later or would have formed or would have been thicker; the seasonal effect
of reduced winter snow cover decreasing at those latitudes which still recieve sunlight in the winter would not be so delayed).
Northeast Pacific coastal warming since 1900 is often ascribed to anthropogenic greenhouse forcing, whereas multidecadal
temperature changes are widely interpreted in the framework
of the Pacific Decadal Oscillation (PDO), which responds to
regional atmospheric dynamics.
There will be Regionally / locally and temporal variations; increased
temperature and backradiation tend to reduce the diurnal
temperature cycle on land, though
regional variations in cloud feedbacks and water vapor could cause some regions to have the opposite effect;
changes in surface moisture and humidity also
changes the amount
of convective cooling that can occur for the same
temperature distribution.
Forcing
changes of similar magnitude, due to water vapour variations, are measurable as
regional temperature changes in Europe, see Philipona, but aerosol
changes are not...
Also, the term «global pattern
of warming» implies
regional temperature change, which pushes the climate system response discussion to a much higher level
of complexity than when simply talking about
changes in global - mean climate.
As I've written before, while 20 years
of intensifying inquiry has greatly reinforced confidence that humans are influencing climate in ways that could profoundly disrupt human and natural affairs, it has not substantially clarified climate outcomes that matter most: how fast and far
temperatures and seas will rise in the next 100 years, how hurricanes will respond to warming, how
regional conditions will
change.
While the anomalous nature
of recent trends in global average
temperature is often highlighted in discussions
of climate
change,
changes at
regional scales have potentially greater societal significance.
An assessment
of the relationship between significant observed
changes from Section 1.3 and significant
regional temperature changes is presented in Section 1.4.2.3.
A NASA animation showing
regional temperature changes on a map
of the Earth from 1880 - 2011.
High - frequency associations (not shown here) remain strong throughout the whole record, but average density levels have continuously fallen while
temperatures in recent decades have risen... As yet, the reason is not known, but analyses
of time - dependent
regional comparisons suggest that it is associated with a tendency towards loss
of «spring» growth response (Briffa et al., 1 999b) and, at least for subarctic Siberia, it may be connected with
changes in the timing
of spring snowmelt (Vaganov et al., 1999).
A new study released Friday in the journal Science Advances helps clear up a bit
of the mystery, by showing that man - made climate
change is responsible for most
of the
change seen in ocean surface
temperatures near the equator across Asia, which in turn affect
regional rainfall patterns including the Indian monsoon.
Accordingly, there is less certainty about the
changes in frequency and intensity
of tropical cyclones on a
regional basis than for
temperature and precipitation
changes.
A central topic will be teleconnections in the climate system, i.e. how a
change in climate in one part
of the globe (e.g.
temperatures in the Atlantic or shrinking sea ice cover in the Arctic) can influence climate on other parts
of the globe (e.g. Eurasian winter
temperatures), and how we can use this information to improve
regional climate prediction and therefore
regional climate service.
The Great Lakes, North America's largest freshwater feature, have recently recorded higher water
temperatures and less ice cover as a result
of changes in
regional climate (see also Ch.
So while CET can be expected to track global
temperature (Lamb's thesis), this is somewhat masked by this additional
regional climate
change, as reflected in the transition from regularity to chaos in its Hale curve around mid-18th century (one reason for preferring HadCRUT3 over CET in identifying multidecadal components
of climate
change for recent centuries).
[1]
Changing population dynamics and uneven
temperature emergence combine to exacerbate
regional exposure to heat extremes under 1.5 °C and 2 °C
of warming, Environmental Research Letters, February 2018
Global mean surface
temperatures are only one way to assess the full impact
of fossil fuel emissions and they do not reflect the
regional aspects and ever - growing complexity
of our
changing climate.
As such, wouldn't
changes in wind direction likely be a
regional influence and not a global influence — kind
of moving around which areas are «stuck» from one part
of the globe to another without
changing the overall
temperature balance
of the globe?
This is a strong indication that agriculture, and not
changing sea surface
temperature, caused the
regional changes in climate during the last third
of the 20th century, the researchers say.
Morice, C. P., J. J. Kennedy, N. A. Rayner, and P. D. Jones, 2012: Quantifying uncertainties in global and
regional temperature change using an ensemble
of observational estimates: The HadCRUT4 dataset.
The Swedish Meteorological and Hydrological Institute (SMHI) presents unique data which depict
regional climate
change after a rise in global
temperature of 1.5 degrees.
They clearly have not «proved» skill at predicting in a hindcast mode,
changes in climate statistics on the
regional scale, and even in terms
of the global average surface
temperature trend, in recent years they have overstated the positive trend.
Changes in instrumentation and data availability have caused time - varying biases in estimates
of global - and
regional - average sea - surface
temperature.
[2] Bhend J, Whetton P (2013) Consistency
of simulated and observed
regional changes in
temperature, sea level pressure and precipitation.
During the past century land use
change has given rise to
regional changes in the local surface climatology, particularly the mean and variability
of near surface
temperature (Pitman et al, 2012).
Its primary usefulness is as an indicator
of global or large scale
regional temperature changes.