At the surface, the variability
of temperatures over land is much greater than that over the oceans (Fig. 4), which reflects the very different heat capacities of the underlying surface and the depth of the layer linked to the surface.
Not exact matches
When traveling
over colder water, and
land especially, the storm loses most
of the energy that it gains from the high
temperatures.
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.
Land and Ocean Combined: The combined average temperature over global land and ocean surfaces for August 2014 was the record highest for the month, at 61.45 °F (16.35 °C), or 1.35 °F (0.75 °C) above the 20th century average of 60.1 °F (15.6
Land and Ocean Combined: The combined average
temperature over global
land and ocean surfaces for August 2014 was the record highest for the month, at 61.45 °F (16.35 °C), or 1.35 °F (0.75 °C) above the 20th century average of 60.1 °F (15.6
land and ocean surfaces for August 2014 was the record highest for the month, at 61.45 °F (16.35 °C), or 1.35 °F (0.75 °C) above the 20th century average
of 60.1 °F (15.6 °C).
Warmer than average
temperatures were evident
over most
of the global
land surface, except for parts
of western Europe, northern Siberia, parts
of eastern Asia and much
of central Australia stretching north.
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 the business - as - usual scenario comes with large climate changes the world
over and would create entirely new patterns
of temperature and precipitation for 12 to 39 percent
of Earth's
land area.
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.
Warmer than average
temperatures were evident
over most
of the global
land surfaces, except for parts
of the United States and western Europe, northern Siberia, parts
of eastern Asia and much
of central Australia stretching north.
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.
According to the
Land & Ocean
Temperature Percentiles map above, monthly record warmth was observed
over much
of northern Canada, far northwestern Russia, southern Japan, the Philippines, part
of southwestern China, and central southern Africa.
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 observed fact that
temperatures increases slower
over the oceans than
over land demonstrates that the large heat capacity
of the ocean tries to hold back the warming
of the air
over the ocean and produces a delay at the surface but nevertheless the atmosphere responds quit rapidly to increasing greenhouse gases.
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.
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.
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.
With higher precipitation, portions
of this snow may not melt during the summer and so glacial ice can form at lower altitudes and more southerly latitudes, reducing the
temperatures over land by increased albedo as noted above.
There are some various proposed mechanisms to explain this that involve the surface energy balance (e.g., less coupling between the ground
temperature and lower air
temperature over land because
of less potential for evaporation), and also lapse rate differences
over ocean and
land (see Joshi et al 2008, Climate Dynamics), as well as vegetation or cloud changes.
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.
Record high
temperatures over land surfaces were measured across Far East Russia, Alaska, far western Canada, a swath
of the eastern United States, much
of Central America and northern South America, southern Chile, much
of eastern and western Africa, north central Siberia, parts
of south Asia, much
of southeast Asia island nations and Papua New Guinea, and parts
of Australia, especially along the northern and eastern coasts.
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 impossible.
Here we show that, globally,
temperatures over land have risen as much on windy nights as on calm nights, indicating that the observed overall warming is not a consequence
of urban development.
---- It would actually be really interesting to see a series
of plots that show how the datasets
of measured sea and
land temperatures have evolved
over time as they have been improved with adjustments such as this.
The two longest ones are
of temperature near the Earth's surface: a vast network
of weather stations
over land areas, and ship data from the oceans.
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.
A model
of the imperfections is needed to enable the compensation, and the teams who provide values
of global
temperature each use a different model for the imperfections (i.e. they make different selections
of which points to use, they provide different weightings for e.g. effects
over ocean and
land, and so on).
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.
Surface
temperatures over land haven't gone up much, but that's not the only or even the best way to measure the amount
of warming.
Verify using data collected only
over the 1/3
of the planet that is covered with
land strikes me as odd, particularly because we expect the
land temperatures to rise faster than ocean
temperatures.
«Global surface
temperature trends, based on
land and marine data, show warming
of about 0.8 deg C
over the last 100 years.
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.
Animation 1 compares the GISS
land surface air
temperature trends to UAH lower troposphere
temperature trends
over land for the period
of 1979 to 2012.
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.
Spring drying
of the
land surface
over Europe was an important factor in the occurrence
of the extreme 2003
temperatures.
It's hard to imagine how Cowtan and Way could determine with any degree
of certainty how «the hybrid method works best
over land and most importantly sea ice» when there is so little surface air
temperature data
over sea ice.
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.
Since the TAR, the observational basis
of analyses
of extremes has increased substantially, so that some extremes have now been examined
over most
land areas (e.g., daily
temperature and rainfall extremes).
Diurnal
temperature range (DTR) has decreased
over land by about 0.4 °C
over the last 50 years, with most
of that change occurring prior to 1980 (Section 3.2.2.1).
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.
However, the critical threshold R C is independent
of ɛ, and thus the calculation depends only on relatively robust averaged values
of precipitation, net radiation, average
temperature difference between
land and ocean, specific humidity
over ocean, and the natural constants ρ, L, and C p.