Sentences with phrase «climate feedback strength»

We welcome model or observational studies on changes in climate feedback strength or the emergence of new feedbacks; changes in modes of variability; new climate nonlinearities; fundamental climate zone shifts; and qualitatively new impacts on to life emerging in hot or cold climates.

Not exact matches

Using historical aerial photo analysis, soil and methane sampling, and radiocarbon dating, the project quantified for the first time the strength of the present - day permafrost carbon feedback to climate warming.

We don't know this, nor the nature and strength of natural feedbacks in the climate system that might drive future warming».

Although the strength of this feedback varies somewhat among models, its overall impact on the spread of model climate sensitivities is reduced by lapse rate feedback, which tends to be anti-correlated.

Time - variation of the global climate feedback arises naturally when the pattern of surface warming evolves, actuating regional feedbacks of different strengths.

The margin of error in various «forcings» and feedback loop strengths is so big that there is a reasonable probability that global climate will cool in the next decade.

I wonder what would happen if the same approach was applied to other climate metrics, like sea surface temperature, water vapor feedback strength, and precipitation - evaporation changes.

«By comparing the response of clouds and water vapor to ENSO forcing in nature with that in AMIP simulations by some leading climate models, an earlier evaluation of tropical cloud and water vapor feedbacks has revealed two common biases in the models: (1) an underestimate of the strength of the negative cloud albedo feedback and (2) an overestimate of the positive feedback from the greenhouse effect of water vapor.

«Understanding how the tropical forest responds to big droughts and heat waves help us to evaluate the strength of carbon - climate feedback..

Polar amplication is of global concern due to the potential effects of future warming on ice sheet stability and, therefore, global sea level (see Sections 5.6.1, 5.8.1 and Chapter 13) and carbon cycle feedbacks such as those linked with permafrost melting (see Chapter 6)... The magnitude of polar amplification depends on the relative strength and duration of different climate feedbacks, which determine the transient and equilibrium response to external forcings.

This failure is a little strange as the assessed scale of future permafrost CH4 emissions are plain within the paper's Fig 6 while Section 6.4 — Sensitivity of Permafrost Methane Fluxes to Climate Change concludes «The potential strength of the permafrost CH4 feedback may be considered small through to 2100 but remains uncertain at these and longer timescales.»

Understanding how the tropical forest responds to big droughts and heat waves help us to evaluate the strength of carbon - climate feedback in ESMs, allowing us to better understand and predict climate change over coming decades.

That is to say, because the strength of the feedbacks are themselves variable, the true climate sensitivity (not just our ability to know what it is) is inherently uncertain.

Time - variation of the global climate feedback arises naturally when the pattern of surface warming evolves, actuating regional feedbacks of different strengths.

In essence, what Roe and Baker show is that this characteristic shape arises from the non-linear relationship between the strength of climate feedbacks (f) and the resulting temperature response (deltaT), which is proportional to 1 / (1 - f).

Therefore, the allowable CO2 concentration also correlates with the strength of the low - cloud feedback in climate models (see our paper for a figure).

The amplitudes of the pre-industrial, decadal - scale NH temperature changes from the proxy - based reconstructions (< 1 °C) are broadly consistent with the ice core CO2 record and understanding of the strength of the carbon cycle - climate feedback.

BBD, «The net strength of positive feedbacks determines climate sensitivity.

The net strength of positive feedbacks determines climate sensitivity.

All climate models used in the reports of the Intergovernmental Panel on Climate Change (IPCC) take into account the feedback related to plants, which slows down climate change, but its strength has been difficult to esclimate models used in the reports of the Intergovernmental Panel on Climate Change (IPCC) take into account the feedback related to plants, which slows down climate change, but its strength has been difficult to esClimate Change (IPCC) take into account the feedback related to plants, which slows down climate change, but its strength has been difficult to esclimate change, but its strength has been difficult to estimate.

To stabilize our chattering climate, we'll need to identify all of the important feedbacks that control climate and ocean currents, and estimate their relative strength and interactions.

[¶]... Basing our assessment on a combination of several independent lines of evidence, as summarised in Box 10.2 Figures 1 and 2, including observed climate change and the strength of known feedbacks simulated in GCMs, we conclude that the global mean equilibrium warming for doubling CO2, or «equilibrium climate sensitivity», is likely to lie in the range 2 °C to 4.5 °C, with a most likely value of about 3 °C.

Clouds especially are a challenge to incorporate into climate models, and different assumptions — all of which reasonable — can exert an uncomfortably powerful influence over the strength of amplifying feedbacks.

'' it is suggested that the strength of the tropical low - cloud feedback predicted by the IPSL - CM5A model in climate projections might be overestimated by about fifty percent.»

If the strength of these feedbacks were to change, that the impact on climate of human emissions will change.

Taken together, the evidence strongly favours a combined water vapour - lapse rate feedback of around the strength found in global climate models.»

This is how a spatial and seasonal reorganisation of TSI entrains * strongly positive * feedbacks which combine with enough strength to propel the climate system out of a glacial into an interglacial.

The main reasons are that (i) other forcing and feedback factors may co-vary in a statistically dependent way with CO2 and can not be separated, (ii) the operation of some climate feedbacks depends on the time scale considered, and (iii) the strength of climate feedbacks depends on the mean climate.

The assumption used in A&H (following F&G) is that p (O S) has the same Gaussian form as function of O for each value of S when O is not an estimate of climate sensitivity but of feedback strength or L.

Truly only one negative feedback in the planet's overall carbon cycle can act with sufficient speed and strength to avert catastrophic climate impacts: The dominant carbon - based life form on this planet will have to respond to the already painfully clear impacts of our carbon emissions by slashing those emissions sharply and eventually running the planet on carbon - negative power.

The lack of a unique natural measure in the space of continuous parameters like climate sensitivity S or feedback strength Y or any of the infinite number of equivalent functions is an essential problem with the present amount of empirical data.

76) Dr Roy Spencer, a principal research scientist at the University of Alabama in Huntsville, has indicated that out of the 21 climate models tracked by the IPCC the differences in warming exhibited by those models is mostly the result of different strengths of positive cloud feedback — and that increasing CO2 is insufficient to explain global - average warming in the last 50 to 100 years.

The MIT model permits one to systematically vary the model's climate sensitivity (by varying the strength of the cloud feedback) and rate of mixing of heat into the deep ocean and determine how the goodness - of - fit with observations depends on these factors.

Basically, TCR depends on how the temperature responds to the strength of feedbacks (a determinant of climate sensitivity) and the rate at which this occurs as a function of ocean heat uptake.

We need greater attention on the strength of uncertain processes and feedbacks in the physical climate system (e.g. carbon cycle feedbacks, ice sheet dynamics)(NRC 2013), as well as on institutional and behavioral feedbacks associated with energy production and consumption, to determine scientifically plausible bounds on total warming and the overall behavior of the climate system (Heal and Millner 2014).

It is a measure of the strengths of the climate feedbacks at a particular time and may vary with forcing history and climate state.

28 Estimated Strength of Water Vapor Feedback Earliest studies suggest that if the absolute humidity increases in proportion to the saturation vapor pressure (constant relative humidity), this will give rise to a water vapor feedback that will double the sensitivity of climate compared to an assumption of fixed absolute hFeedback Earliest studies suggest that if the absolute humidity increases in proportion to the saturation vapor pressure (constant relative humidity), this will give rise to a water vapor feedback that will double the sensitivity of climate compared to an assumption of fixed absolute hfeedback that will double the sensitivity of climate compared to an assumption of fixed absolute humidity.

Incorporating new findings on the radiative forcing of black carbon (BC) aerosols, the magnitude of the climate sensitivity, and the strength of the climate / carbon cycle feedbacks into a simple upwelling diffusion / energy balance model similar to the one that was used in the TAR, we find that the range of projected warming for the 1990 - 2100 period is reduced to 1.1 - 2.8 °C.

The apparent mechanism is that such mixing dehydrates the low - cloud layer at a rate that increases as the climate warms, and this rate of increase depends on the initial mixing strength, linking the mixing to cloud feedback.

However, the timing, strength, and overall role of dust − climate feedbacks over these cycles remain unclear.

Unlike Charney climate sensitivity, which is related to the strength of feedbacks involving short timescale climate processes such as those involving clouds and water vapor, Earth System sensitivity also integrates feedbacks involving long timescale changes in the cryosphere, terrestrial vegetation, and deep ocean circulation.

Eisenman (2012) discusses how differences in the strength of various climate feedbacks can lead to differences in the likelihood of hysteresis in the Arctic sea ice system.

The basic results of this climate model analysis are that: (1) it is increase in atmospheric CO2 (and the other minor non-condensing greenhouse gases) that control the greenhouse warming of the climate system; (2) water vapor and clouds are feedback effects that magnify the strength of the greenhouse effect due to the non-condensing greenhouse gases by about a factor of three; (3) the large heat capacity of the ocean and the rate of heat transport into the ocean sets the time scale for the climate system to approach energy balance equilibrium.

Several methods have been used to diagnose climate feedbacks in GCMs, whose strengths and weaknesses are reviewed in Stephens (2005) and Bony et al. (2006).

Hall and Qu (2006) show that biases of a number of MMD models in reproducing the observed seasonal cycle of land snow cover (especially the spring melt) are tightly related to the large variations in snow albedo feedback strength simulated by the same models in climate change scenarios.

«Determining the strength and even the direction, positive or negative, of the feedbacks in the CLAW hypothesis has proved one of the most challenging aspects of research into the role of the sulfur cycle on climate modification.»

The strength of many amplifying feedbacks is likely to increase with warming, which could increase the risk of the climate changing state (Box 3).

In simulations by atmosphere - only CMIP5 models driven by evolving SST patterns (AMIP simulations), if the observed historical evolution of SST patterns is used feedback strength is much greater (climate sensitivity is lower) than if the historical evolution of SST simulated by coupled CMIP5 models is used.

This range in climate sensitivity is attributable to differences in the strength of «radiative feedbacks» between models and is one of the reasons why projections of future climate change are less certain than policy makers would like.

Models differ considerably in their estimates of the strength of different feedbacks in the climate system, particularly cloud feedbacks, oceanic heat uptake and carbon cycle feedbacks, although progress has been made in these areas.