Sentences with phrase «modeled vegetation carbon»

We find, when all seven models are considered for one representative concentration pathway × general circulation model combination, such uncertainties explain 30 % more variation in modeled vegetation carbon change than responses of net primary productivity alone, increasing to 151 % for non-HYBRID4 models.

Not exact matches

With global climate models projecting further drying over the Amazon in the future, the potential loss of vegetation and the associated loss of carbon storage may speed up global climate change.

Based on satellite monitoring and models that estimate the carbon released from burning vegetation (plus or minus 50 percent), the group reckons that U.S. fires produce 290 million metric tons of carbon per year, equal to about 5 percent of the nation's annual emissions from fossil fuels.

General circulation models have generally excluded the feedback between climate and the biosphere, using static vegetation distributions and CO2 concentrations from simple carbon - cycle models that do not include climate change6.

Sitch, S., et al., 2003: Evaluation of ecosystem dynamics, plant geography and terrestrial carbon cycling in the LPJ dynamic global vegetation model.

For instance, the sensitivity only including the fast feedbacks (e.g. ignoring land ice and vegetation), or the sensitivity of a particular class of climate model (e.g. the «Charney sensitivity»), or the sensitivity of the whole system except the carbon cycle (the Earth System Sensitivity), or the transient sensitivity tied to a specific date or period of time (i.e. the Transient Climate Response (TCR) to 1 % increasing CO2 after 70 years).

With the aid of global Earth observations and data - driven models, the researchers show that on average, extreme events prevent the uptake of around 3 petagrams carbon per year by the vegetation.

Dr Chris Jones Lead researcher in vegetation and carbon cycle modelling Met Office Hadley Centre

[Response: The models that include a carbon cycle and dynamic vegetation should have such effects — but this is still a rather experimental class of models.

General circulation models have generally excluded the feedback between climate and the biosphere, using static vegetation distributions and CO2 concentrations from simple carbon - cycle models that do not include climate change6.

Considering the carbon - cycle feedback, some models (e.g. Cox et al.) estimate large positive vegetation feedback (increased soil respiration, lower photosynthesis due to increased vegetation stress, increased fire frequency...) and some of the most extreme scenarios predict the CO2 concentration to be up to 980 ppm.

Wårlind, D., Smith, B., Hickler, T., and Arneth, A.: Nitrogen feedbacks increase future terrestrial ecosystem carbon uptake in an individual - based dynamic vegetation model, Biogeosciences, 11, 6131 - 6146, doi: 10.5194 / bg -11-6131-2014, 2014 link

Peter Cox is the originator / author of the Triffid dynamic global vegetation model which was used to predict dieback of the Amazonian rain forest by 2050 and as a consequence a strong positive climate - carbon cycle feedback (i.e., an acceleration of global warming) with a resultant increase in global mean surface temperature by 8 deg.

Within an international model intercomparison project, researchers were able to simulate the complex carbon cycle as well as vegetation dynamics in climate projections for the 21st century.

5 looked in more detail at the responses of three of these DGVMs in the Amazon region, and found that although all three models simulated reductions in vegetation carbon, they did this for different reasons.

Evaluation of the terrestrial carbon cycle, future plant geography and climate - carbon cycle feedbacks using five Dynamic Global Vegetation Models (DGVMs)

In addition, Earth system models predict carbon loss by placing vegetation at a given point, and then changing various climate properties above it.

Analyses of differences in model behavior should therefore focus not only on the processes of carbon acquisition (i.e., photosynthesis and NPP), but also on the dynamics of vegetation carbon turnover.

«Most Earth system models don't predict this, which means they overestimate the amount of carbon that high - latitude vegetation will store in the future,» he adds.

However, global - scale vegetation model development has strongly focused on productivity processes whereas, apart from major disturbances such as fire, the dynamics of carbon turnover have been largely ignored.

(A — C) Change in annual global mean vegetation carbon (A), NPP (B), and residence time of carbon in vegetation (C) under the HadGEM2 - ES RCP 8.5 climate and CO2 scenario for seven global vegetation models.

Along the way, the vegetation will relinquish more trapped carbon than most current climate models predict.

Future global vegetation carbon change calculated by seven global vegetation models using climate outputs and associated increasing CO2 from five GCMs run with four RCPs, expressed as the change from the 1971 — 1999 mean relative to change in global mean land temperature.

Previous modeling studies have also consistently predicted increased global vegetation carbon under future scenarios of climate and CO2, but with considerable variation in absolute values (2 — 4).

Vegetation carbon -LRB--RRB- was predicted to increase by an average of 270 Pg C from preindustrial levels across the models by 2100, but saturating NPP and increasing heterotrophic respiration led to a reduction in NEP after 2050.

To conduct their study, the researchers used a spatial model of marsh morphodynamics into which they incorporated recently published observations from field experiments on marsh vegetation response to varying levels of atmospheric carbon dioxide.

As a result, the new model found that the increase in carbon uptake by more vegetation will be overshadowed by a much larger amount of carbon released into the atmosphere.

Specific research topics include carbon dioxide, methane and water fluxes and their reservoirs in vegetation and soil, transport in atmosphere, and model - data fusion using advanced numerical methods.The research is based on numerical modelling, from local to global scale with focus on northern regions.

Earth System Models are mathematical descriptions of the real world at the cutting edge of understanding how our planet works and the links between the main components of the oceans, vegetation, ice and desert, gases in the atmosphere, and the carbon cycle, as well as numerous other components.

Thirdly, Earth system models have begun to incorporate more realistic and dynamic vegetation components, which quantify positive and negative biotic feedbacks by coupling a dynamic biosphere to atmospheric circulations with a focus on the global carbon cycle (Friedlingstein et al., 2003, 2006; Cox et al., 2004, 2006).

While this research has been underway, GFDL scientists have also embarked on extensive development of the land surface model, including integrated and detailed treatment of surface and groundwater hydrology as well as dynamic vegetation including the carbon cycle and human land use / alteration.

Using complex computer models, the team concluded that on average, vegetation absorbs 11 billion fewer metric tons of carbon dioxide than it would in a climate that doesn't experience extreme weather events.

But once you took all of this into account, you might as well throw in the carbon cycle, vegetation (albedo), soil (albedo), cloud formation (albedo, etc.), evaporation from soil, the spectra for the sun and its luminosity, solar cycles, and once you do that you pretty much have the entire climate model, including how it evolves over time — or there abouts.

Climate models today are extremely flexible and configurable tools that can include all these Earth System modules (including those mentioned above, but also full carbon cycles and dynamic vegetation), but depending on the application, often don't need to.

The term Earth System Model is a little ambiguous with some people reserving that for models that include a carbon cycle, and others (including me) using it more generally to denote models with more interactive components than used in more standard (AR4 - style) GCMs (i.e. atmospheric chemistry, aerosols, ice sheets, dynamic vegetation etc.).

There are a couple of lines in IPCC Working Group I («New coupled climate - carbon models (Betts et al., 2004; Huntingford et al., 2004) demonstrate the possibility of large feedbacks between future climate change and vegetation change, discussed further in Section 7.3.5 (i.e., a die back of Amazon vegetation and reductions in Amazon precipitation).»).

Allen et al in Nature 30 April 2009, SI, stated explicitly (SI, p. 6) «the terrestrial carbon cycle model has both vegetation and soil components stores.