Sentences with phrase «atmospheric concentrations over»

Despite this, increased production has led to a rapid increase in its atmospheric concentration over the past decade.

Not exact matches

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).

Curiously, the decline in atmospheric oxygen over the past 800,000 years was not accompanied by any significant increase in the average amount of carbon dioxide in the atmosphere, though carbon dioxide concentrations do vary over individual ice age cycles.

The increased use of synthetic chemicals, including pesticides and pharmaceuticals to attack unwanted organisms, has outpaced the rates of change in rising atmospheric CO2 concentrations and other agents of global environmental change over the past 45 years, a new Duke - led analysis reveals.

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 milliOver 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 milliover its preindustrial level of 280 ppm (parts per million).

Averaged over the entire globe, it's one - fourth as large as the heating caused by increasing atmospheric CO2 concentrations during the same period.

The region between 45 degrees N and 65 degrees N saw the lowest ever concentrations of total atmospheric ozone over the three continental regions of North America, Europe and Siberia in the winter - spring months of 1992 and 1993.

Just last month, the World Meteorological Organization reported that atmospheric CO2 concentrations are still rising at an unprecedented pace, despite the plateau in emissions over the last few years (Climatewire, Oct. 31).

«During photosynthesis plants bind atmospheric carbon, whose isotopic composition is preserved in resins over millions of years, and from this, we can infer atmospheric oxygen concentrations,» explains Ralf Tappert.

Stable atmospheric concentrations of greenhouse gases would lead to continued warming, but if carbon dioxide emissions could be eliminated entirely, temperatures would quickly stabilize or even decrease over time.

The letter notes that «Stable atmospheric concentrations of greenhouse gases would lead to continued warming, but if carbon dioxide emissions could be eliminated entirely, temperatures would quickly stabilize or even decrease over time.

In one sentence: Scientists at Pacific Northwest National Laboratory determined that high concentrations of nitrogen oxides influence the creation of the brown haze that hangs over the world's megacities, providing new insights that can create higher accuracy climate and atmospheric models.

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

• The methanetrack.org website has shown significant increases in atmospheric methane concentrations over Antarctica this austral winter (which I believe are due to increases in methane emissions from the Southern Ocean seafloor due to increases in the temperature of bottom water temperatures), and if this trend continues, then the Southern Hemisphere could be a significant source of additional atmospheric methane (this century).

However, atmospheric CO2 content plays an important internal feedback role.Orbital - scale variability in CO2 concentrations over the last several hundred thousand years covaries (Figure 5.3) with variability in proxy records including reconstructions of global ice volume (Lisiecki and Raymo, 2005), climatic conditions in central Asia (Prokopenko et al., 2006), tropical (Herbert et al., 2010) and Southern Ocean SST (Pahnke et al., 2003; Lang and Wolff, 2011), Antarctic temperature (Parrenin et al., 2013), deep - ocean temperature (Elder eld et al., 2010), biogeochemical conditions in the Northet al., 2008).

When fossil CO2 increases atmospheric concentrations it comes into equilibrium with that in the oceans mostly over about a year, but continues slowly over around 10 years.

That's why, over the long term, it is the atmospheric concentration of CO2 (which, by the way, is now hovering around 400 ppm) that will determine the severity of climate change.

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 reason for scientific concern over global warming rests on basic physics — infrared absorption — and robust measurements of atmospheric gas concentrations.

With a lifetime of ~ 10 years, spreading emissions over 30 - year period would of course reduce the peak atmospheric burden (though CH4 lifetime would presumably increase with higher CH4 concentration).

- atmospheric CO2 d13C decrease over the last decades means it's CO2 added from biomass - atmospheric CO2 d14C decrease over the last decades means it's fossil CO2 - atmospheric O2 concentration decrease over the last decades means it's burning

They should be able to withstand the predicted increase of 0.00007 atmospheric CO2 concentration over the next century.

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.

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.

It is a fact that atmospheric concentrations of CO2 have varied widely over geological time.

Thus any process which tends to favor the growth of organisms made from silicate, such as diatoms, over organisms made from carbonate, such as the coccolithophorids, will tend to lower the atmospheric CO2 concentration — and vice versa — even if the total organic biomass formed in the surface layer and sinking from that layer remains constant.

All that said, we can draw the conclusion that the theoretical effects of CO2 do in fact exist, they have been measured over a 10 cm path length, and from this we can extrapolate that a still higher sensitivity would be arrived at once the entire atmospheric scale and the change in water vapour concentration from bottom to top of that scale is taken into account.

As the Trump administration charges forward with its war on science by canceling a «crucial» carbon monitoring system at NASA, scientists and climate experts are sounding alarms over atmospheric concentrations of carbon dioxide (CO2) that just surpassed a «troubling» threshold for the first time in human history.

The increase in atmospheric CO2 concentration over each year is the residual of the natural variations in atmospheric CO2 concentration within each year.

And over that time period humans have emitted over 30 % of ALL the CO2 emissions they EVER emitted, and the atmospheric concentration has reached all - time record levels.

Can you describe very specific changes in bacterial mass and metabolism that over the course of a century would not only significantly increase atmospheric CO2 concentration but also increase the ratios of C12 to C13 and C14 in the manner that has been observed (we'll leave out the bookkeeping from industrial records that also must be accounted for)?

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.

Indeed, this is why I have repeatedly said to you: «Any assessment of the causes of the rise of atmospheric CO2 concentration over a period of years requires assessment of the changes that occur each year (because the annual increase to CO2 in the atmosphere is the residual of the seasonal changes to CO2 in the atmosphere).»

Utterly wrong: the computer climate models on which predictions of rapid warming from enhanced atmospheric greenhouse gas concentration cowdungare based «run hot,» simulating two to three times the warming actually observed over relevant periods

In the ensuing report we present a meta - analysis of the peer - reviewed scientific literature, examining how the productivities of Earth's plants have responded to the 20th and now 21st century rise in global temperature and atmospheric CO2, a rise that climate alarmists claim is unprecedented over thousands of years (temperature) to millions of years (CO2 concentration).

When Oreskes quotes, ««Human activities... are modifying the concentrations of atmospheric constituents... that absorb or scatter radiant energy... [M] ost of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas emissions», her quotation is accurate and she actually emphasizes the word likely.

First, the computer climate models on which predictions of rapid warming from enhanced atmospheric greenhouse gas concentration are based «run hot,» simulating two to three times the warming actually observed over relevant periods — during which non-anthropogenic causes probably accounted for some and could have accounted for all the observed warming — and therefore provide no rational basis for predicting future GAT.

The graph of the atmospheric concentration of sulfates over the last two thousand years resembles — what's that shape like?

However, a clear understanding of how national emissions reductions commitments affect global climate change impacts requires an understanding of complex relationships between atmospheric ghg concentrations, likely global temperature changes in response to ghg atmospheric concentrations, rates of ghg emissions reductions over time and all of this requires making assumptions about how much CO2 from emissions will remain in the atmosphere, how sensitive the global climate change is to atmospheric ghg concentrations, and when the international community begins to get on a serious emissions reduction pathway guided by equity considerations.

The analysis of Tans (2009) shows that the highest atmospheric CO2 concentration likely to occur over the foreseeable future is only 500 ppm

(Calculating this difference over a 12 - month interval effectively removes the seasonal variation in atmospheric CO2 concentration.)

Comparison of global lower troposphere temperature anomaly over the oceans (blue line) to a model based on the first derivative of atmospheric CO2 concentration at Mauna Loa (red line).

Here, FOR values are derived from a General Circulation Model by extracting OLR and SLE over areas in east - central Europe (at about 60 ° N) one hour after injecting appropriate CO2 concentration (adjustments to the atmospheric profile are thus excluded) to the Feb. 1 midnight simulation.

The analysis of Tans (2009) shows that the highest atmospheric CO2 concentration likely to occur over the foreseeable future is only 500 ppm, so there is likely to be no significant decline in the calcification status of any of the 18 organisms studied by Ries et al., as suggested by our analysis of the similar findings of Watson et al. (2009).

That is an incredible bit of hand - waving there, and completely contradicted by the basic math — atmospheric concentration increase has been less than our emissions for about the last 60 + years, meaning nature is acting as a net sink over that period.

A set of GCM simulations dedicated to quantify the effect of land use change relative to changes in the atmospheric greenhouse gas concentration over the past century revealed that the land use effect is largely limited to the area of land use change.

«What our study shows is that observed water vapor concentrations are high enough and temperatures are low enough over the U.S. in summertime to initiate the chemistry that is known to lead to ozone losses,» said Harvard atmospheric scientist David Wilmouth, one of the paper's co-authors, in an email.

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.»

If we were to engineer as sudden increase in C12 and C13 — containing CO2 in the atmosphere, then measure the decrease of the atmospheric concentration of these two isotopes over time, we would have answered the basic question above by direct measurement.

As a matter of fact, over this period of rapid growth of both human population and GDP, the compounded annual growth rate (CAGR) of atmospheric CO2 concentration was 0.42 % per year.