Sentences with phrase «model than greenhouse gases»

Not exact matches

«More than 1,400 researchers and stakeholders worldwide use the DNDC Model on over 40 agricultural crops to assess the effects of various management practices on greenhouse gas emissions,» said Allison Jordan, CSWA executive director.

Over the past forty years, the ice cover in summer has shrunk by more than half, with climate model simulations predicting that the remaining half might be gone by mid-century unless greenhouse gas emissions are reduced rapidly.

Algae production consumes more energy, has higher greenhouse gas emissions and uses more water than other biofuel sources, like corn, switch grass and canola, Clarens and his colleagues found by using a statistical model to compare growth data of algae with conventional crops.

The new estimates, which are based on an integrated modeling framework that combines information about population, economics, and land use and land productivity, show that Europe could potentially reduce greenhouse gas emissions from land use by more than 60 % by 2050.

For the RCP8.5 projections, which represents stronger increases in greenhouse gas concentrations than RCP4.5, there was a striking level of consistency in the magnitude of change in AR frequency — all models showed an approximate doubling of the number of future ARs compared to the simulations for 1980 — 2005.

Rather than using complex computer models to estimate the effects of greenhouse - gas emissions, Lovejoy examines historical data to assess the competing hypothesis: that warming over the past century is due to natural long - term variations in temperature.

Among the implications of the study are that ocean temperatures in this area may be more sensitive to changes in greenhouse gas levels than previously thought and that scientists should be factoring entrainment into their models for predicting future climate change.

After six years of running such simulations, the verdict is in: Increasing greenhouse gas concentrations as a result of burning fossil fuels and cutting down forests increased the risks of flooding in two out of three model runs by more than 90 percent.

More than 60 models to choose from More than 40 hybrid vehicle models are available in the United States, and more than 20 PEVs will be available in the next two years, prompted by policies to reduce greenhouse gas emissions.

Indeed, the observed warming during the 20th century can not be explained other than by assuming that the models are reasonably accurate in their response to greenhouse gases.

From at least Lorius et al (1991)-- when we first had reasonable estimates of the greenhouse gases from the ice cores, to an upcoming paper by Schneider von Deimling et al, where they test a multi-model ensemble (1000 members) against LGM data to conclude that models with sensitivities greater than about 4.3 ºC can't match the data.

That's according to research out of Stanford University, which analyzed more than 50 climate model simulations of 21st century temperatures under elevated greenhouse gas levels.

Future forecasts of climate models forced with greenhouse gas levels as high as modern ones tend to result in Pliocene - like climate (~ 3 million years ago) when sea levels were estimated to be 14 meters higher than they are today.

Using Mg / Ca paleothermometry from the planktonic foraminifera Globigerinoides ruber from the past 500 k.y. at Ocean Drilling Program (ODP) Site 871 in the western Pacific warm pool, we estimate the tropical Pacific climate sensitivity parameter (λ) to be 0.94 — 1.06 °C (W m − 2) − 1, higher than that predicted by model simulations of the Last Glacial Maximum or by models of doubled greenhouse gas concentration forcing.

The new study used calculations and models to show that the cooling from this change caused surface temperatures to increase about 25 percent more slowly than they would have otherwise, due only to the increases in carbon dioxide and other greenhouse gases.

These myriad unmodeled amplifying feedbacks support the analysis that the climate is much more sensitive to changes in greenhouse gas emissions and other «forcings» than the IPCC models have been saying.

In addition, the ARB says this Honda model has lower greenhouse gas emissions than the fleet average standard required by all cars in 2025, the equivalent of a 50 - percent reduction from current required levels.

Olympus Mons, What it would take is a new model that explained climate better than the current one and a) had a CO2 sensitivity lower than 1 degree per doubling; or b) had a large negative feedback that somehow kicked in right at the current terrestrial temperature range; or c) had a mechanism whereby CO2 suddenly stopped being a greenhouse gas at 280 ppmv

The precise magnitude of the anthropogenic contribution remains uncertain, but in nine out of ten cases our model results indicate that twentieth - century anthropogenic greenhouse gas emissions increased the risk of floods occurring in England and Wales in autumn 2000 by more than 20 %, and in two out of three cases by more than 90 %.

Using Mg / Ca paleothermometry from the planktonic foraminifera Globigerinoides ruber from the past 500 k.y. at Ocean Drilling Program (ODP) Site 871 in the western Pacific warm pool, we estimate the tropical Pacific climate sensitivity parameter (λ) to be 0.94 — 1.06 °C (W m − 2) − 1, higher than that predicted by model simulations of the Last Glacial Maximum or by models of doubled greenhouse gas concentration forcing.

Future forecasts of climate models forced with greenhouse gas levels as high as modern ones tend to result in Pliocene - like climate (~ 3 million years ago) when sea levels were estimated to be 14 meters higher than they are today.

Global climate models have successfully predicted the rise in temperature as greenhouse gases increased, the cooling of the stratosphere as the troposphere warmed, polar amplification due the ice - albedo effect and other effects, greater increase in nighttime than in daytime temperatures, and the magnitude and duration of the cooling from the eruption of Mount Pinatubo.

[T] he last 10 to 15 years «make it more plausible that the size of climate response to greenhouse gas increase is on the lower side of what models have been projecting over the last 10 or 20 years rather than over the high side.»

The second argument is that it is claimed that computer models are now powerful and accurate enough to replicate temperature given the inputs of greenhouse gas forcing and natural forcing (this is what Nordhaus shows in footnote 4) a graph with both is much more accurate than with just natural forcing.

In a recent interview, Nordhaus - whose models project a smaller economic impact than most - said that regardless of whether the models showing larger or smaller economic impacts from climate change are correct, «We've got to get together as a community of nations and impose restraints on greenhouse gas emissions and raise carbon prices.

Because the new precise observations agree with existing assessments of water vapor's impact, researchers are more confident than ever in model predictions that Earth's leading greenhouse gas will contribute to a temperature rise of a few degrees by the end of the century.

Coupled models simulate much less warming over the 20th century in response to solar forcing alone than to greenhouse gas forcing (Cubasch et al., 1997; Broccoli et al., 2003; Meehl et al., 2004), independent of which solar forcing reconstruction is used (Chapter 2).

Kevin Hamilton, who co-authored the report, warns: «If our model results prove to be representative of the real global climate, then climate is actually more sensitive to perturbations by greenhouse gases than current global models predict, and even the highest warming predictions would underestimate the real change we could see.»

However, although models simulate a decrease in DTR when they include anthropogenic changes in greenhouse gases and aerosols, the observed decrease is larger than the model - simulated decrease (Stone and Weaver, 2002, 2003; Braganza et al., 2004).

This rise is larger and probably faster than any such change over the past 9,000 years.Climate models are far from perfect, and they rely on projections of future greenhouse gas emissions that are far from certain.

[12] In fact, using the Model for the Assessment of Greenhouse Gas Induced Climate Change developed by researchers at the National Center for Atmospheric Research, even if all carbon dioxide emissions in the United States were effectively eliminated, there would be less than two - tenths of a degree Celsius reduction in global temperatures.

HadCM3 is a mid-high sensitivity model that produces a greater temperature response to a given amount of greenhouse gas emissions than does PCM, a low - sensitivity model.

Comparisons of direct measurements with satellite data and climate models suggest that the oceans of the southern hemisphere have been sucking up more than twice as much of the heat trapped by our excess greenhouse gases than previously calculated.

No, in particular the aerosol response has a very different structure in models than the well - mixed greenhouse gases, since the forcing is primarily in the Northern Hemisphere, a difference that forms the basis for most attempts in the detection / attribution literature to separate responses to aerosol from well - mixed greenhouse gases.

BESS is a model developed at the University of Nebraska as a more updated alternative than the widely used GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model developed by the U.S. Argonne National Laboratory.

I'm puzzled by your assignment of only a 30 percent probability to the proposition that «Global climate model simulations that include anthropogenic forcing (greenhouse gases and pollution aerosol) provide better agreement with historical observations in the second half of the 20th century than do simulations with only natural forcing (solar and volcanoes).»

Global climate model simulations that include anthropogenic forcing (greenhouse gases and pollution aerosol) provide better agreement with historical observations in the second half of the 20th century than do simulations with only natural forcing (solar and volcanoes).

The errors were four times larger than the assumed impact of man - made greenhouse gases, a fact that seriously compromises the integrity of the computer model.

2.10 All model simulations, whether they were forced with increased concentrations of greenhouse gases and aerosols or with increased concentrations of greenhouse gases alone, show the follow - ing features: greater surface warming of the land than of the sea in winter; a maximum surface warming in high northern latitudes in winter... All these changes are associated with identifiable physical mechanisms.

«Observational analyses have shown the width of the tropical belt increasing in recent decades as the world has warmed... we use a climate model with detailed aerosol physics to show that increases in heterogeneous warming agents — including black carbon aerosols and tropospheric ozone — are noticeably better than greenhouse gases at driving expansion, and can account for the observed summertime maximum in tropical expansion.

In terms of your request for something substantial, I responded to your original claim that «the theory relies on computer models» with a link to a RealClimate post that shows this claim is not correct — rather than computer models, the foundations of the scientific consensus on anthropogenic climate change are built upon our understanding of how the atmosphere works and how we are changing it by emitting greenhouse gases.

The bottom line is that Wilson was not suggesting that solar activity is responsible for more warming than we think, or greenhouse gases less, but merely asking the question «what if models weight solar irradiance more strongly?»

«the 1700 - present greenhouse gas forcing is more than double the 1700 - present solar forcing and hence the warming trend over that period in the model is driven mainly by GHGs.»

And this all supports the analysis that the climate is much more sensitive to changes in greenhouse gas emissions and other «forcings» than the IPCC models have been saying and that a doubling of atmospheric concentrations of carbon dioxide from preindustrial levels to 550 ppm will ultimately warm the planet far more than 3 °C, as NASA's James Hansen argues (see «Long - term» climate sensitivity of 6 °C for doubled CO2).

«In our mor recent global model simulations the ocean heat - uptake is slower than previously estimated, the ocean uptake of carbon is weaker, feedbacks from the land system as temperature rises are stronger, cumulative emissions of greenhouse gases over the century are higher, and offsetting cooling from aerosol emissions is lower.

The simulated three - dimensional spatial pattern of the temperature changes induced by increasing concentrations of a well - mixed greenhouse gas, such as carbon dioxide, is complicated and varies from model to model, but one common aspect is the tendency for the lower to mid-troposphere to warm more rapidly than the surface, except over high latitudes.

Second, the «warming» from CO2 — and yes, CO2 is a «greenhouse gas» — has been much less than predicted by the climate models Obama bases his policies on.

The aerosol cooling in the models may be wrong to some extent, but is almost certainly in the ballpark enough so that the aerosols have compensated for the greenhouse gas effects on hurricane intensity to a significant degree, even if the exact degree is different than what's shown in our paper.

«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.

Early in 2018, it announced it was about to stop producing more than 500 car models that do not meet its air quality standards, thus reducing greenhouse gas emissions.