Average air
temperatures over land in the Arctic have increased by 3 °C since the beginning of the 20th century.
The very strong correlation between observed dryness and high
temperatures over land in the tropics during summer highlights the important role moisture plays in moderating climate.
The SST was largely irrelevant in these scenarios, as the small change in ocean temperature pales in comparison to the large change in atmospheric
temperature over the land in the central US.
Not exact matches
As a result, avian
temperature responses generally involve moving up or down
in elevation rather than stretching or shrinking their ranges
over land.
The World Bank estimates that
over the next 15 years, the global economy will require $ 89 trillion
in infrastructure investments across cities, energy and
land - use systems, and $ 4.1 trillion
in incremental investment for the low - carbon transition to keep within the internationally agreed limit of a 2 - degree - Celsius
temperature rise.
Land - use changes
over the past 250 years
in Europe have been huge, yet, they only caused a relatively small
temperature increase, equal to roughly 6 % of the warming produced by global fossil fuel burning, Naudts noted.
While Earth's landmass has warmed by about 1 degree Celsius (about 2 degrees Fahrenheit)
over the past century, on average,
land temperatures in the Arctic have risen almost 2 C (3.6 F).
According to NOAA scientists, the globally averaged
temperature over land and ocean surfaces for August 2014 was the highest for August since record keeping began
in 1880.
Pielke, who said one issue ignored
in the paper is that
land surface
temperature measurements
over time show bigger warming trends than measurements from higher up
in a part of the atmosphere called the lower troposphere, and that still needs more explanation.
In addition, the data density and geographic extent of this study is far greater than most previous studies because
over 16,000 stream
temperature sites were used with thousands of biological survey locations to provide precise information at scales relevant to
land managers and conservationists.
The experiments showed that, if Antarctica's
land height is reduced,
temperatures in the region respond more strongly to a rise
in the concentration of greenhouse gases
over the continent.
They found that AP increased faster than air
temperature (AT)
over land in the past few decades, especially
in the low latitude areas, and the rise is expected to continue
in the future.
Using updated and corrected
temperature observations taken at thousands of weather observing stations
over land and as many commercial ships and buoys at sea, the researchers show that
temperatures in the 21st century did not plateau, as thought.
This translates into an average
temperature rise of 4.3 C
over land in the northern hemisphere where most of the world's population lives, and even more
in urban areas.
However, for the globe as a whole, surface air
temperatures over land have risen at about double the ocean rate after 1979 (more than 0.27 °C per decade vs. 0.13 °C per decade), with the greatest warming during winter (December to February) and spring (March to May)
in the Northern Hemisphere.
Surface specific humidity has generally increased after 1976
in close association with higher
temperatures over both
land and ocean.
Pierre, could you comment on what, exactly, is new
in the recent Philipona paper, compared with the two similar papers they published last year («Greenhouse forcing outweighs decreasing solar radiation driving rapid
temperature rise
over land», «Radiative forcing — measured at Earth's surface — corroborate the increasing greenhouse effect»)?
In addition to the surface data described above, measurements of
temperature above the surface have been made with weather balloons, with reasonable coverage
over land since 1958, and from satellite data since 1979.
The Nature article comes as climate scientists published what they said today was the «best ever» collection of evidence for global warming, including
temperature over land, at sea and
in the higher atmosphere, along with records of humidity, sea - level rise, and melting ice.
Warming has occurred
in both
land and ocean domains, and
in both sea surface
temperature (SST) and nighttime marine air
temperature over the oceans.
Global mean
temperatures averaged
over land and ocean surfaces, from three different estimates, each of which has been independently adjusted for various homogeneity issues, are consistent within uncertainty estimates
over the period 1901 to 2005 and show similar rates of increase
in recent decades.
The forcing
over the last 150 years is around 1.6 W / m2 (including cooling effects from aerosols and
land use change) but the climate is not (yet)
in equilibirum, and so the full
temperature response has not been acheived.
Land surface
temperatures (LSTs)
in January 2014
over Australia monitored by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite.
And finally, current theories based on greenhouse gas increases, changes
in solar, volcanic, ozone,
land use and aerosol forcing do a pretty good job of explaining the
temperature changes
over the 20th Century.
The globally averaged
temperature over land and ocean surfaces for 2015 was the highest among all years since record keeping began
in 1880.
The climate
in most places has undergone minor changes
over the past 200 years, and the
land - based surface
temperature record of the past 100 years exhibits warming trends
in many places.
«We show that at the present - day warming of 0.85 °C about 18 % of the moderate daily precipitation extremes
over land are attributable to the observed
temperature increase since pre-industrial times, which
in turn primarily results from human influence,» the research team said.
The «bounce» seen
in November 2010 was driven by record - warm
temperature anomalies
in the Northern Hemisphere, particularly
over land.
In addition, since the global surface temperature records are a measure that responds to albedo changes (volcanic aerosols, cloud cover, land use, snow and ice cover) solar output, and differences in partition of various forcings into the oceans / atmosphere / land / cryosphere, teasing out just the effect of CO2 + water vapor over the short term is difficult to impossibl
In addition, since the global surface
temperature records are a measure that responds to albedo changes (volcanic aerosols, cloud cover,
land use, snow and ice cover) solar output, and differences
in partition of various forcings into the oceans / atmosphere / land / cryosphere, teasing out just the effect of CO2 + water vapor over the short term is difficult to impossibl
in partition of various forcings into the oceans / atmosphere /
land / cryosphere, teasing out just the effect of CO2 + water vapor
over the short term is difficult to impossible.
With the anthropogenic perturbation likely to be around 2C and maybe more
in the next 100 years (that's a global average, it will be much more
over northern hemisphere
land where we actually live), there are simply no comparable sources of natural variability, and the historical record shows that such
temperatures have not been approached
in the last 2000 years.
All of the discussion about accelerating increases
in temperature that I've read
over the last couple of years pin the effect on feedbacks.Particularly changes
in the
land.
Thus, small changes of global average air
temperature are associated with very large changes
in some regions, particularly
over land, at mid - to high latitudes,
in mountain regions.
The paper
in Nature Climate Change, «
Temperature and vegetation seasonality diminishment
over northern
lands,» pulls together a wide array of research, including the work by Bruce Forbes of the University of Lapland last year, on what I called «pop - up forests» — patches of rapidly - growing tundra shrubs.
Seems to me the debate about AGHG global warming and increasing TC frequency / intensity / duration boils down to the fact that as sea surface
temperatures, as well as deeper water
temperatures rise, the wallop of any TC
over warmer seas without mitigating circumstances like wind sheer and dry air off
land masses entrained
in the cyclone will likely be much more devastating.
And at last they have found a new one: they suggest that the difference
in the
temperature increase
over land and the oceans during the last decades might be due to contaminations of the
land temperature record — They call it an anomalous behaviour — ignoring that it corresponds fully to what is physically expected.
«One of the most significant signals
in the thermometer - observed
temperature record since 1900 is the decrease
in the diurnal
temperature range
over land, largely due to warming of the minimum
temperatures... Climate models have
in general not replicated the change
in diurnal
temperature range well.
As far as I am aware,
temperatures of the atmosphere close to the surface, rather than the actual surface, are usually measured
over land, unless measured remotely by satellites,
in which case the
temperature of the material overlaying the Earth's surface is measured, rarely the surface itself.
In the summer months,
land temperatures are higher than sea
temperatures and the heaviest showers occur
over eastern England.
Temperatures over land and ocean have gone up 0.8 ° Celsius (1.4 ° Fahrenheit), on average,
in that span:
Notably, by studying the clouds
over a limited region of the atmosphere
over the eastern Pacific Ocean, as well as
over nearby
land masses, the team at the university's International Pacific Research Centre have declared themselves firmly
in the latter camp, warning that, as
temperatures continue to creep steadily upwards
over the next 100 years, cloud cover will become thinner and more - sparse, thereby serving to exacerbate the problem.
Surface
temperatures over land regions have warmed at a faster rate than
over the oceans
in both hemispheres.
Temperature change from climate models, including that reported in 1988 (12), usually refers to temperature of surface air over both land
Temperature change from climate models, including that reported
in 1988 (12), usually refers to
temperature of surface air over both land
temperature of surface air
over both
land and ocean.
Similarly, if there is an increase
in the difference between
land and ocean
temperatures, the rising air
over land draws
in moist air from the ocean and lifts it, leading to monsoons.
Spring drying of the
land surface
over Europe was an important factor
in the occurrence of the extreme 2003
temperatures.
By comparing modelled and observed changes
in such indices, which include the global mean surface
temperature, the
land - ocean
temperature contrast, the
temperature contrast between the NH and SH, the mean magnitude of the annual cycle
in temperature over land and the mean meridional
temperature gradient
in the NH mid-latitudes, Braganza et al. (2004) estimate that anthropogenic forcing accounts for almost all of the warming observed between 1946 and 1995 whereas warming between 1896 and 1945 is explained by a combination of anthropogenic and natural forcing and internal variability.
The combined average
temperature over global
land and ocean surfaces for April 2016 was 1.98 °F above the 20th century average — the highest
temperature departure for April since global records began
in 1880.
This warming can be seen
in measurements of troposphere
temperatures measured by weather balloons and satellites,
in measurements of ocean heat content, sea surface
temperature (measured
in situ and by satellites), air
temperatures over the ocean, air
temperature over land.
Figure 1 shows the change
in the world's air
temperature averaged
over all the
land and ocean between 1975 and 2008.
[Response: I guess you missed the part about them only showing correlation with short - term fluctuations — nothing at all to do with any «70 - yr cycle» —
in temperature over land only.
So for us people with some engineering experience, that gives us an intuitive feel for why
temperatures are hotter
over land than what is
in the average SST data.