Meehl and Teng recently showed that when this is done, thereby turning a model projection into a hindcast, the models reproduced the observed trends — accelerated warming in the 1970s and
reduced rate of surface warming during the last 15 years — quite well.
Our results support previous findings of
a reduced rate of surface warming over the 2001 — 2014 period — a period in which anthropogenic forcing increased at a relatively constant rate.»
The combined effect of all these changes is actually to
reduce the rate of surface warming over the past 100 years compared to what we see in the raw temperature data.
Not exact matches
When greenhouse gases increase, more longwave radiation is directed back at the ocean
surface, which
warms the cool - skin layer, lowers the thermal gradient, and consequently
reduces the
rate of heat loss.
«It has been claimed that the early - 2000s global
warming slowdown or hiatus, characterized by a
reduced rate of global
surface warming, has been overstated, lacks sound scientific basis, or is unsupported by observations.
The increased troposphere -
surface warming from more CO2 is best thought
of by the
rate of IR escape out the top
of the atmosphere, which is
reduced for a given temperature.
Temperature tends to respond so that, depending on optical properties, LW emission will tend to
reduce the vertical differential heating by cooling
warmer parts more than cooler parts (for the
surface and atmosphere); also (not significant within the atmosphere and ocean in general, but significant at the interface betwen the
surface and the air, and also significant (in part due to the small heat fluxes involved, viscosity in the crust and somewhat in the mantle (where there are thick boundary layers with superadiabatic lapse
rates) and thermal conductivity
of the core) in parts
of the Earth's interior) temperature changes will cause conduction / diffusion
of heat that partly balances the differential heating.
Although there have been many suggestions for possible contributions to the slowdown
of the recent
warming rate, a
reduced warming rate of the Pacific sea
surface temperature seems to be a significant factor.
Whereas the CO2 has
reduced the
rate of uplift in the ascending column (which
warms the
surface) CO2 at lower levels
reduces the
rate of descent in the descending column which
reduces surface temperature because less warmth is then being generated via compression
of descending air.
That
warming on descent also
reduces the
rate of temperature decline with height which suppresses convection from the
surface so that the
surface on the day side then
warms more than it otherwise would have done and the
surface on the night side cools less quickly than it otherwise would have done..
You write: «If internal variability (such a a cool PDO phase)
reduces the
rate of increase
of surface temperature, while the e [x] ternal forcing still is increasing, this means the radiative imbalance is impeded from being cancelled by
surface warming.»
If internal variability (such a a cool PDO phase)
reduces the
rate of increase
of surface temperature, while the eternal forcing still is increasing, this means the radiative imbalance is impeded from being cancelled by
surface warming.
AGW climate scientists seem to ignore that while the earth's
surface may be
warming, our atmosphere above 10,000 ft. above MSL is a refrigerator that can take water vapor scavenged from the vast oceans on earth (which are also a formidable heat sink), lift it to cold zones in the atmosphere by convective physical processes, chill it (removing vast amounts
of heat from the atmosphere) or freeze it, (removing even more vast amounts
of heat from the atmosphere) drop it on land and oceans as rain, sleet or snow, moisturizing and cooling the soil, cooling the oceans and building polar ice caps and even more importantly, increasing the albedo
of the earth, with a critical negative feedback determining how much
of the sun's energy is reflected back into space, changing the moment
of inertia
of the earth by removing water mass from equatorial latitudes and transporting this water vapor mass to the poles,
reducing the earth's spin axis moment
of inertia and speeding up its spin
rate, etc..
However, if extra CO2
reduces the cooling
rate of the Earth
surface, and the
rate of radiant energy transfer from Sun to Earth
surface is little changed, then the Earth
surface will
warm (other things being equal) from what it was before the increase in CO2.
«Climate science» as it is used by warmists implies adherence to a set
of beliefs: (1) Increasing greenhouse gas concentrations will
warm the Earth's
surface and atmosphere; (2) Human production
of CO2 is producing significant increases in CO2 concentration; (3) The
rate of rise
of temperature in the 20th and 21st centuries is unprecedented compared to the
rates of change
of temperature in the previous two millennia and this can only be due to rising greenhouse gas concentrations; (4) The climate
of the 19th century was ideal and may be taken as a standard to compare against any current climate; (5) global climate models, while still not perfect, are good enough to indicate that continued use
of fossil fuels at projected
rates in the 21st century will cause the CO2 concentration to rise to a high level by 2100 (possibly 700 to 900 ppm); (6) The global average temperature under this condition will rise more than 3 °C from the late 19th century ideal; (7) The negative impact on humanity
of such a rise will be enormous; (8) The only alternative to such a disaster is to immediately and sharply
reduce CO2 emissions (
reducing emissions in 2050 by 80 % compared to today's
rate) and continue further reductions after 2050; (9) Even with such draconian CO2 reductions, the CO2 concentration is likely to reach at least 450 to 500 ppm by 2100 resulting in significant damage to humanity; (10) Such reductions in CO2 emissions are technically feasible and economically affordable while providing adequate energy to a growing world population that is increasingly industrializing.
I have been engaged in a discussion with a young climatology professional who thought that evaporation from the ocean
surface left behind a residue
of surplus energy to
warm the oceans by
reducing the
rate of energy release from the oceans and thus justifying the AGW scenario.
If we regress the annual
rate of CO2 change against temperature, we are likely to see a significant short term temperature effect as
warming reduces the solubility
of CO2 in the
surface ocean layers (with effects on terrestrial sinks as well).
North Atlantic
surface warming decreases water density there, thus
reducing the
rate of sinking.
The Sea
of Japan has an acidification
rate 27 % higher at depth than at the
surface, showing how
reduced ventilation from
warming could impact the deep ocean.
Five - year averaging
reduces differences among temperature datasets, showing that since the mid-1970s the global
surface air temperature has on average increased by 0.1 °C every five to six years, although the
rate of warming, viewed from a five - year perspective, has not been steady.
The
rate of global
warming will result in
reduced water density near the
surface both directly as the result
of surface layers expanding due to increased temperature and indirectly due to the fresh water from melts resulting in decreased salinity.