Sentences with phrase «current atmospheric concentrations»

It's not like carbon dioxide is a poison at current atmospheric concentrations.

In addition, the Endangerment Rule authorizes or obligates EPA to establish: (1) greenhouse gas emission standards for heavy trucks, marine vessels, aircraft, locomotives, and other non-road vehicles and engines; (2) greenhouse gas performance standards for potentially dozens of industrial source categories; and, (3) national ambient air quality standards (NAAQS) for greenhouse gases set below current atmospheric concentrations.

Despite a half century of climate change that has significantly affected temperature and precipitation patterns and has already had widespread ecological and hydrological impacts, and despite a near certainty that the United States will experience at least as much climate change in the coming decades, just as a result of the current atmospheric concentrations of greenhouse gases, those organizations in the public and private sectors that are most at risk, that are making long - term investments and commitments, and that have the planning, forecasting and institutional capacity to adapt, have not yet done so.

Yet even if appropriate measures were taken today to reduce global emissions by 80 percent by 2050, current atmospheric concentrations of carbon dioxide and other long - lived greenhouse gases are already such that the next 50 years of climate change can not be averted.

Current atmospheric concentrations of GHGs are significantly higher than pre-industrial levels as a result of human activities.

As noted in Chapter 8, Section 8.4.2, at the time of the SAR most coupled models had difficulty in reproducing a stable climate with current atmospheric concentrations of greenhouse gases, and THEREFORE NON-PHYSICAL «FLUX ADJUSTMENT TERMS» WERE ADDED.

Although plants grown in high levels of carbon dioxide — say, double the current atmospheric concentrations — initially grow rapidly, the growth tapers off within weeks and the plants wind up with a low protein content.

About half of this near - term warming represents a «commitment» to future climate change arising from the inertia of the climate system response to current atmospheric concentrations of greenhouse gases.

This test was not only about CO2 over sixty times the current atmospheric concentration, but also cold and low O2 and other factors, so it's of limited use, one hopes, in a discussion of expected atmospheric levels of CO2.

Noting that the current atmospheric concentration of CO2 is higher than it's been in the past 650,000 years, the IPCC predicts that human - induced climate change could spell extinction for 20 to 30 percent of the world's species by the end of this century, cause increasingly destructive weather patterns, and flood coastal cities.

The report confirms that the current atmospheric concentration of carbon dioxide, a critical heat - trapping gas, «exceeds by far the natural range over the last 650,000 years.»

The current atmospheric concentration of carbon dioxide is estimated to be about 385 ppm.

By some calculations, the tar sands contain the equivalent of about 200 parts per million CO2 — or roughly half the current atmospheric concentration.

Sulfate aerosols wash out pretty quickly, so their current atmospheric concentration (and the resulting negative forcing) is mainly determined by the current emissions levels.

Not exact matches

What current atmospheric carbon dioxide concentration tells us about the need to stabilise the global climate and the need for a step change in government, city and business action.

Current climate change is characterized by rising atmospheric carbon dioxide (CO2) concentrations and associated warming.

Gavin addresses «societal inertia» — the likelihood that the strict criteria of «immediate zero CO2 emissions» will actually be met (as opposed to the easier but also unlikely possibility that we could hold current atmospheric CO2 concentrations steady through immediate 60 - 70 + % emission reduction).

there has been 15 to 25 times more CO2 than current concentrations; the claim that this time we will reach a tipping point is alarmist, ludicrous, and totally without foundation,» declared atmospheric scientist Robert W. Endlich on July 12, 2009.

If current trends continue, we will raise atmospheric CO2 concentrations to double pre-industrial levels during this century.

The consensus is that several factors are important: atmospheric composition (the concentrations of carbon dioxide, methane); changes in the Earth's orbit around the Sun known as Milankovitch cycles (and possibly the Sun's orbit around the galaxy); the motion of tectonic plates resulting in changes in the relative location and amount of continental and oceanic crust on the Earth's surface, which could affect wind and ocean currents; variations in solar output; the orbital dynamics of the Earth - Moon system; and the impact of relatively large meteorites, and volcanism including eruptions of supervolcanoes.

Current atmospheric CO2 concentrations are probably the highest that Earth has experienced over at least the past three - million years.

Although NAAQS regulation of lead was both technologically and economically feasible, not even a global depression lasting several decades would suffice to lower atmospheric carbon dioxide concentrations below current levels.

As NOAA's Mauna Loa measurement of atmospheric methane concentrations are only currently increasing at a rate of approximately 0.25 % per year (or 12.5 % change in 50 - years); how could anyone be concerned that the change in atmospheric methane burden in 50 - years could be 300 % (as per Isaken et al (2011) case 4XCH4; which would require an additional 0.80 GtCH4 / yr of methane emissions on top of the current rate of methane emissions of 0.54 GtCH4 / yr)?

If we knew ocean heat uptake as well as we know atmospheric temperature change, then we could pin down fairly well the radiative imbalance at the top of the atmosphere, which would give us a fair indication of how much warming is «in the pipeline» given current greenhouse gas concentrations.

(hint, they assumed a 1 % / yr increase in atmospheric CO2 concentration from present day for 80 years — the current rate (depending on how you define «current» is some where between 0.5 and 0.6 % / yr).

The Solomon Committee report amplifies this conclusion when it confirms that we observe, in any year, only 50 % of the warming to which we have committed the planet by allowing atmospheric concentrations of greenhouse gases to rise to the then current level.

Current concentrations of atmospheric carbon dioxide and methane far exceed pre-industrial values found in polar ice core records of atmospheric composition dating back 650,000 years.

Current evidence suggests that that the concentrations of atmospheric CO2 predicted for the year 2100 will have major implications for plant physiology and growth.

bozza @ 354, even emissions at 10 % of current rates would be sufficient to keep on increaseing atmospheric CO2 concentrations, and ergo prevent net ocean outgassing of CO2.

... current climate modeling is essentially to answer one question: how will increased atmospheric concentrations of CO2 (generated from human activity) change earth's temperature and other climatological statistics?

This is true because most mainstream scientists have concluded that the world must reduce total global emissions by at the very least 60 to 80 percent below existing levels to stabilize GHG atmospheric concentrations at minimally safe atmospheric GHG concentrations and the United States is a huge emitter both in historical terms and in comparison to current emissions levels of other high emitting nations.

However, at some point in time, air capture conceivably could be a useful tool to mitigate emissions from distributed sources, and may even be deployed to reduce atmospheric concentrations of CO2 below current concentrations.

The study tested an increase in atmospheric carbon dioxide concentrations to 950 parts per million by 2100, more than twice the current level.

My calculations from this does show a gradually increasing sensitivity (deg C per doubling) beginning at current concentrations (around 400 PPM) and slowly changing from about 0.9 to 1.8 degrees per doubling when the atmospheric concentration gets, theoretically, as high as 18,000 PPM CO2.

It indeed so far has followed the laws of physics and thus the temperature graph is mathematically a good fit for the expected effects of the current CO2 concentrations but not for professed «positive atmospheric feedbacks».

However, I am not a «warmista» by any means — we do not know how to properly quantify the albedo of aerosols, including clouds, with their consequent negative feedback effects in any of the climate sensitivity models as yet — and all models in the ensemble used by the «warmistas» are indicating the sensitivities (to atmospheric CO2 increase) are too high, by factors ranging from 2 to 4: which could indicate that climate sensitivity to a doubling of current CO2 concentrations will be of the order of 1 degree C or less outside the equatorial regions (none or very little in the equatorial regions)- i.e. an outcome which will likely be beneficial to all of us.

Further, the probabilistic approach reveals a picture startling to even most global - warming pessimists: If we're to avoid precipitating what that U.N. Framework Convention genteelly calls «dangerous anthropogenic interference,» we're going to have to aim at an atmospheric greenhouse - gas concentration target that, by current trends, we'll reach in less than two decades.

Many opponents of climate change policies argue that countries like the United States should not have to reduce their ghg emissions until China reduces its emissions by comparable amounts because China is now the largest emitter of all nations in terms of total tons, yet such an argument usually ignores the historical responsibility of countries like the United States which the following illustration reveals is more than twice as responsible for current elevated atmospheric ghg concentrations than China is.

From the above illustration it can be seen that the United States and the EU are more responsible for raising atmospheric concentrations to current dangerous levels than than the rest of the world combined.

From what I've read (one or two slight variations depending on the author), about 7.8 gigatonnes (Gt) of CO2 correspond to 1ppm of CO2 in the atmosphere, so in total there are about 3000Gt (3000 billion tonnes) of CO2 in the atmosphere, based on a current atmospheric CO2 concentration of 392ppm.

The above illustration depicts, in a very abbreviated and sketchy form, that as the scientific evidence of the threat from human - induced climate change became stronger over a 40 - year period and as the US political opposition to climate change policies successfully fought to prevent the adoption of robust US climate policies, the atmospheric concentration of CO2 rose from below 320 ppm (parts per million) to current levels of over 400 ppm.

Our current understanding of the atmospheric emissions for the feedstock of the CFCs, CCl4, does not allow us to predict its concentration in the atmosphere.

Increasing use of fossil carbon at the current rate would drive atmospheric concentrations towards four times pre-industrial figures by 2100.

This means that there is no validity to the comment that this is «still considerably smaller than the estimated rise in temperatures from a continuation of current CO2 emission rates» especially considering the fact that CO2 emissions from humans are definitely not the prime source of the observed increase in atmospheric CO2 concentration.

Given that a case can be made that current levels atmospheric ghg concentrations are already harming or putting people and ecosystems at risk, it is difficult to make an ethically acceptable case that atmospheric ghg concentration targets higher than current levels are justified unless consent is given by those who are already being harmed by warming or full compensation is made to those who through no fault of their own are harmed by climate change.

(Hansen et al 2008) To do this, existing atmospheric concentrations of CO2 must not only not be allowed to rise the small amount to 450 ppm CO2 from current levels of 394 ppm CO2 but must be reduced below existing levels to 350 ppm CO2.

Zbigniew Jaworowski [1994, 1992] has repeatedly pointed to the unreliability of ice - core data to establish pre-1958 CO2 concentrations, thus creating doubt about the magnitude of the human contribution to the current atmospheric CO2 concentration.

So a 2 ppmv per year increase in atmospheric CO2 (at current concentration) results in an annual increase in forcing of 0.03 W / m ^ 2, as well.

«Mere mortals» assume that «doubling of the atmospheric CO2 concentration» starts at the current concentration of ~ 400 ppm and ends a 800 ppm.

At current CO2 concentrations, the 667 wavenumber line is «saturated» in the sense that IR from the surface is absorbed almost completely over a small distance and further increases in CO2 will have minimal effect on its ability to intercept IR and mediate surface and atmospheric warming.