Sentences with phrase «atmospheric concentration levels»

In fact, among the 900 scenarios the report authors examined, if greenhouse gas concentrations remain above current levels in 2030, «many models... could not produce scenarios reaching atmospheric concentration levels that make it as likely as not that temperature change will remain below 2 °C relative to pre ‐ industrial levels.»

A central conclusion of the report is that it is more effective to assess climate stabilization goals using global mean temperature change as a primary metric, rather than atmospheric concentration levels.

As a visually - oriented person, I've assembled a simple video with NASA's temperature anomalies combined with man - made emission and atmospheric concentration levels since 1850.

The numbers on the boxes on these two lines specify the probability of exceeding 2 °C if atmospheric concentration levels are stabilized at these levels.

In addition, because each national emission reduction target commitment must be understood as an implicit position of the nation on safe ghg atmospheric concentration levels, setting national ghg emissions goals must be set with full knowledge of how any national target will affect the global problem.

Here it is useful to note that an atmospheric concentration level close to 550 ppm CO2e would result by 2050 if greenhouse gas emissions simply continued at present levels without any increases in the intervening years.

We now turn to what atmospheric greenhouse gas atmospheric concentrations levels are understood to prevent warming above these amounts.

Not exact matches

At a Feb. 7 hearing of Juliana, et al v. United States of America, et al — a case a group of kids, young adults and environmentalists brought in 2015 against the U.S. government — Frank Volpe said he didn't know whether carbon dioxide levels had reached 400 parts per million, a measurement of atmospheric concentration.

Growth rates for concentrations of carbon dioxide have been faster in the past 10 years than over any 10 - year period since continuous atmospheric monitoring began in the 1950s, with concentrations now roughly 35 percent above preindustrial levels (which can be determined from air bubbles trapped in ice cores).

Moreover, these measurements were made at concentrations of sulfuric acid and dimethylamine corresponding to atmospheric levels (less than 1 molecule of sulfuric acid per 1 x 1013 molecules of air).

Record emissions of carbon dioxide mean atmospheric concentrations have reached levels that lead to the highest temperature increases

Our record is also of interest to climate policy developments, because it opens the door to detailed comparisons between past atmospheric CO2 concentrations, global temperatures, and sea levels, which has enormous value to long - term future climate projections.»

Scientists can determine ancient atmospheric concentrations by measuring CO2 and methane levels in tiny air bubbles trapped in such ice, formed when the ice fell to the earth as snow.

During the early 2000s, environmental scientists studying methane emissions noticed something unexpected: the global concentrations of atmospheric methane (CH4)-- which had increased for decades, driven by methane emissions from fossil fuels and agriculture — inexplicably leveled off.

«Detergent» molecules may be driving fluctuations in atmospheric methane concentrations: New study suggests hydroxyl radicals may be behind unexplained recent increase in methane levels.»

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.

Over the past 250 years, human activities such as fossil fuel burning have raised the atmospheric CO2 concentration by more than 40 % over its preindustrial level of 280 ppm (parts per million).

For their scenario calculations, the AWI modellers plugged in atmospheric CO2 concentrations in excess of 500 ppm, a level in keeping with the forecasts released by the Intergovernmental Panel on Climate Change (IPCC).

The Scripps Institution of Oceanography records of atmospheric carbon dioxide levels show that Jan. 1 was the first day of the new year above that concentration, followed by Jan. 3 and Jan. 7.

Cutting - edge techniques enabled the researchers to detect the presence of gases even at part - per - trillion levels, one million times less concentrated than atmospheric CO2 concentrations.

But this also means that targets such as stabilizing atmospheric concentrations of CO2 at 450 parts per million (nearly double preindustrial levels) to avoid more than a 3.6 degree F (2 degree C) temperature rise are nearly impossible as well.

Continued use of fossil fuels into the 21st century is predicted to lead to atmospheric CO2 levels > 900 ppm by 2100 (under Representative Concentration Pathway (RCP) 8.5; Meinshausen et al., 2011), though the precise level is highly dependent on the emission scenario (Pachauri et al., 2014).

The evidence here is more circumstantial, but Danish researcher Lars - Georg Hersoug notes that atmospheric levels of the gas have risen during the same period and that in the United States, obesity has increased most rapidly on the East Coast, where CO2 concentrations are highest.

If we manage to stabilize CO2 levels at 450 ppmv (the atmospheric CO2 concentration as of 2010 is about 390 ppmv), according to the best estimate, we have a probability of less than 50 % of meeting the 2 °C target.

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

Once global carbon dioxide emissions had been reduced to zero, some combination of atmospheric decay and carbon dioxide extraction, probably partially offset by some level of carbon dioxide re-release from the worlds oceans, might possibly reduce the atmospheric carbon dioxide concentration to comply with the NAAQS.

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.

The most common indicator is the atmospheric background CO2 concentration, the global mean temperature, the global mean sea level, and the area with snow or Arctic sea ice.

According to a conversation I had with Hansen, the reason atmospheric concentration stabilizes is that the ocean sink, that is currently sinking about half of our CO2 emissions, keeps sinking CO2 at around that level so that as we lower emissions at 3 % / year (about 50 % in 20 years) the oceans are sinking most of our emissions and, therefore, keeping atmospheric concentrations stable.

The atmospheric concentrations of carbon dioxide (CO2), methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years.

In view of the present discussion of the role of carbon dioxide in effecting global temperature I would like to know of any laboratory or bench experiments that show a temperature - CO2 concentration curve within the range of currently measured atmospheric CO2 levels.

If the surface ocean pCO2 concentrations continue to increase in proportion with the atmospheric CO2 increase, a doubling of atmospheric CO2 from preindustrial levels will result in a 30 % decrease in carbonate ion concentration and a 60 % increase in hydrogen ion concentration.

We collectively need to demand that there is no acceptable response to climate change other than strong emission reductions, ensuring that atmospheric concentrations of CO2 are returned to 350ppm levels, global temperature rise is kept (at the maximum) 2 °C and, even better, 1.5 °C — to do that, as was emphasized on numerous occasions, we need a F.A.B. climate deal: Fair, Ambitious, and (perhaps most importantly) Binding.

In 2002, the president said: «I reaffirm America's commitment to the United Nations Framework Convention and its central goal, to stabilize atmospheric greenhouse gas concentrations at a level that will prevent dangerous human interference with the climate.»

Transient climate sensitivity: The global mean surface - air temperature achieved when atmospheric CO2 concentrations achieve a doubling over pre-industrial CO2 levels increasing at the assumed rate of one percent per year, compounded.

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.

These measurements, supplemented by analyses of air bubbles trapped in ice core samples, show unequivocally that atmospheric CO2 has increased from a pre-industrial level of 277 ppm in 1750 to present day concentrations that are approaching 390 ppm.

He and eight co-authors have drafted a fresh paper arguing that the world has already shot past a safe eventual atmospheric concentration of carbon dioxide, which they say would be around 350 parts per million, a level passed 20 years ago.

«This perspective article focuses on intervals in time in the fossil record when atmospheric CO2 concentrations increased up to 1200 ppmv, temperatures in mid - to high - latitudes increased by greater than 4 °C within 60 years, and sea levels rose by up to 3 m higher than present.

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

Taking account of their historic responsibility, as well as the need to secure climate justice for the world's poorest and most vulnerable communities, developed countries must commit to legally binding and ambitious emission reduction targets consistent with limiting global average surface warming to well below 1.5 degrees Celsius above preindustrial levels and long - term stabilization of atmospheric greenhouse gas concentrations at well below below 350 p.p.m., and that to achieve this the agreement at COP15 U.N.F.C.C.C. should include a goal of peaking global emissions by 2015 with a sharp decline thereafter towards a global reduction of 85 percent by 2050,

(Keep in mind that various experts and groups have said risks of centuries of ecological and economic disruption rise with every step toward and beyond 450 parts per million, with some scientists, most notably James Hansen of NASA, saying the long - term goal should be returning the atmospheric concentration to 350 parts per million, a level passed in 1988.)

This is about as far as one could get from high levels (relative to most atmospheric concentrations) of methane over large areas high in the atmosphere in the Arctic where there is very little (direct) human activity.

James Hansen, in his book, believes it is possible (or was possible then) to take actions which reduced the atmospheric concentration of CO2 to 350ppm (a level he considers the maximum to have a chance of avoiding catastrophic climate change).

The study projects that a doubling of atmospheric carbon dioxide (CO2) concentrations over pre-industrial levels will increase global temperatures by between 1.2 °C and 2.9 °C, with 1.9 °C being the most likely outcome.

Climate alarm depends on several gloomy assumptions — about how fast emissions will increase, how fast atmospheric concentrations will rise, how much global temperatures will rise, how warming will affect ice sheet dynamics and sea - level rise, how warming will affect weather patterns, how the latter will affect agriculture and other economic activities, and how all climate change impacts will affect public health and welfare.

The results of the analysis demonstrate that relative to the reference case, projected atmospheric CO2 concentrations are estimated by 2100 to be reduced by 3.29 to 3.68 part per million by volume (ppmv), global mean temperature is estimated to be reduced by 0.0076 to 0.0184 °C, and sea - level rise is projected to be reduced by approximately 0.074 — 0.166 cm, based on a range of climate sensitivities.

If we do overshoot our carbon «budget» in the next several decades, the only way to return atmospheric CO2 concentrations to levels that avoid climate change will be to deploy large - scale CDR projects capable of generating net «negative» emissions:

Is is less risky to control concentrations of atmospheric GH gases, or is it better to let them double, or even triple, from pre-industrial levels?

It certainly would be an interesting experiment to throttle back all GHG emissions to a sufficiently low level at which atmospheric concentrations do stabilise.