Sentences with phrase «about atmospheric carbon»

Air bubbles trapped in the ice and chemical clues about atmospheric carbon levels in corals have shown that there is now more carbon dioxide in the air than at any other point in the history of human civilization.

In fact, many climate scientists have been warning about atmospheric carbon levels passing 400 parts per million — which happened last year.

Not exact matches

According to the IEA's projections, if we're going to get serious about holding atmospheric carbon to 450 parts per million our days of increasing oil consumption are at an end.

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.

Meanwhile, atmospheric carbon dioxide levels continue to climb, up about 20 percent over the past half century.

About 6000 years ago, levels of atmospheric carbon dioxide rose — and until now slash - and - burn by the 12 million humans on the planet at the time has been blamed.

Jacobson, the director of Stanford's Atmosphere / Energy Program and a senior fellow at the Woods Institute for the Environment and the Precourt Institute for Energy, said almost 8.5 billion tons of atmospheric carbon dioxide — or about 18 percent of all anthropogenic carbon dioxide emissions - comes from biomass burning.

But the Southern Ocean plays a more benign role in the global carbon budget: Its waters now take up about 50 % of the atmospheric carbon dioxide emitted by human activities, thanks in large part to the so - called «biological pump.»

Global warming is dependent upon the atmospheric CO2 concentration, so we need to care about carbon.

Previously, a massive outpouring of carbon about 56 million years ago had been proposed as faster than the current rate of net increase in atmospheric carbon.

Since methane can cause about 20 times as much atmospheric warming as carbon dioxide, curbing methane would help slow global warming.

[NASA's OCO - 2 Mission in Pictures (Gallery)-RSB- The concentration of atmospheric carbon dioxide — a heat - trapping «greenhouse gas» — has risen from 280 parts per million (ppm) before the Industrial Revolution to about 400 ppm today.

Before the age of industrialization, the amount of atmospheric carbon dioxide was about 280 parts per million (ppm), scientists have determined.

As for the paper's conclusion that removing atmospheric carbon is necessary in order to achieve the 2 ˚C target, climate scientist Richard Moss of the Pacific Northwest National Laboratory's Joint Global Change Research Institute in College Park, Maryland, says that's a nearly impossible goal «with what we know about today.»

And while the cut would stabilize atmospheric carbon dioxide levels, it holds them at about 450 parts - per - million, according to the study.

Together, they confirm estimates from atmospheric chemists that natural tropical forests absorb about a fifth of our carbon emissions.

«Modern atmospheric carbon dioxide levels are today equivalent to those about three million years ago, when sea level was at least six meters higher because the ice sheets were greatly reduced.

Although scientists have measured atmospheric CO2 levels for decades, the current network of ground stations, observatories, aircraft and other instruments emerged during an era when researchers were trying to answer questions about the total amount of carbon dioxide in the atmosphere.

Using specially developed model configurations, the team studies how Arctic whitening would be expected to play out in a world with four times the preindustrial amount of atmospheric carbon dioxide, and an Arctic that is about 10 degrees Celsius hotter (18 degrees Fahrenheit).

But with that see - saw battle going on in the tropics, the result was that overall, tropical forests» impact on atmospheric carbon dioxide was a wash - deforestation emitted about the same amount that was captured in forest growth.

It concluded that atmospheric carbon dioxide concentrations had already increased by about 25 percent in the past century, and continued use of fossil fuels would lead to substantial temperature increases in the future.

Such models could help environmental planners cultivate microbial mixes that achieve a desired end — which could be soil that locks up gigatons of atmospheric carbon, or that sloughs off pollution with ease, or that yields the kinds of grapes vintners dream about.

After the start of the Deccan eruptions and the resulting rise in atmospheric carbon dioxide, local temperatures warmed about 7.8 degrees C (14 degrees F).

It also acts as a carbon sink — absorbing about 30 % of atmospheric CO2 released from human activities such as burning fossil fuels...

If we pin atmospheric carbon dioxide concentration to right about 300 to 320 ppm, we are looking at 20 - 30 thousand years of stable climate, with huge fresh water reserves, and we are only about half way into a global mass extinction.

Using our carbon cycle model we calculate that if we extract 100 ppm of CO2 from the air over the period 2030 — 2100 (10/7 ppm per year), say storing that CO2 in carbonate bricks, the atmospheric CO2 amount in 2100 will be reduced 52 ppm to 358 ppm, i.e., the reduction of airborne CO2 is about half of the amount extracted from the air and stored.

Raymond Pierrehumbert, an Oxford University atmospheric physics professor who believes cutting carbon dioxide emissions is more urgent than cutting methane emissions, said Howarth's research offers little new information about the role of natural gas production in global warming.

While volcanoes contribute only about 1 percent of the total global carbon dioxide emitted, they provide a direct link between underground reservoirs of carbon in the mantle and atmospheric carbon dioxide.

Radio - carbon - dating Synonyms, Radio - carbon Because atmospheric carbon 14 arises at about the same rate that the atom decays.

Although there are no reliable observations, atmospheric concentrations of carbon dioxide about 100 years ago, at about the start of the industrial revolution, are estimated to have been on the order of 270 to 290 parts per million (ppm).

But with atmospheric carbon climbing at an annual rate of 2 ppm and expected to accelerate to 3 ppm, levels could approach 900 ppm by the end of the next century, and conditions that bring about the beginnings of ocean anoxia may be in place.

The uptake is about 2.5 % of the total amount of «excess» or «disequilibrium» atmospheric carbon.

The total human contribution to atmospheric carbon dioxide since the start of the industrial revolution has been estimated at about 25 % [6].

and 1998 snippets Methane now contributes about 20 % to the increased direct radiative forcing by greenhouse gases compared to preindustrial times [Shine et al., 1995] Oxidation of CH4 in the troposphere produces carbon monoxide (CO), can lead production of ozone (03), and involves atmospheric oxidant, the hydroxyl radical (OH).

Doubling of atmospheric carbon dioxide is an oft - talked - about threshold, and today's climate models include accepted values for the climate's sensitivity to doubling.

Even if climate sensitivity is somewhat less than the IPCC's median value of about 3 degrees Celsius, atmospheric carbon dioxide levels are increasing exponentially, so a smaller value merely buys an extra decade or two until the same amount of warming is reached.

If we pin atmospheric carbon dioxide concentration to right about 300 to 320 ppm, we are looking at 20 - 30 thousand years of stable climate, with huge fresh water reserves, and we are only about half way into a global mass extinction.

«Due to human activities such as the combustion of fossil fuels and deforestation, and the increased release of CO2 from the oceans due to the increase in the Earth's temperature, the concentration of atmospheric carbon dioxide has increased by about 35 % since the beginning of the age of industrialization.»

The trouble is that there remains little empirical evidence to support the idea, as we were surprised to find out when we talked to UC San Diego atmospheric physicist Veerabhadran Ramanathan about his research showing that another type of aerosol — black carbon — had a significant warming effect:

«Since the pre-industrial era, we have increased atmospheric CO2 [or carbon dioxide] concentration by about 100 parts per million, so this is really a different dimension,» she said.

For example, atmospheric carbon dioxide grew by approximately 30 % during the transition from the most recent cold glacial period, about 20,000 years ago, to the current warm interglacial period; the corresponding rate of decrease in surface ocean pH, driven by geological processes, was approximately 50 times slower than the current rate driven largely by fossil fuel burning.

They find that the effects of climate change and the increasing concentration of atmospheric carbon dioxide on plants have contributed to them drawing down about 44 more grams of carbon per square metre, every year since the 1980s, compared to pre-industrial conditions.

The work in question takes measurements from one locale, and doesn't publish conclusions, rather Doney's statements are giving his opinion about what he read, «Long - term ocean acidification trends are clearly evident over the past several decades in open - ocean time - series and hydrographic survey data, and the trends are consistent with the growth rate of atmospheric carbon dioxide (Dore et al., 2009).»

John Carter August 8, 2014 at 12:58 am chooses to state his position on the greenhouse effect in the following 134 word sentence: «But given the [1] basics of the greenhouse effect, the fact that with just a very small percentage of greenhouse gas molecules in the air this effect keeps the earth about 55 - 60 degrees warmer than it would otherwise be, and the fact that through easily recognizable if [2] inadvertent growing patterns we have at this point probably at least [3] doubled the total collective amount in heat absorption and re-radiation capacity of long lived atmospheric greenhouse gases (nearly doubling total that of the [4] leading one, carbon dioxide, in the modern era), to [5] levels not collectively seen on earth in several million years — levels that well predated the present ice age and extensive earth surface ice conditions — it goes [6] against basic physics and basic geologic science to not be «predisposed» to the idea that this would ultimately impact climate.»

We know the planet will warm between about 1.5 and 4.5 °C in response to the increased greenhouse effect from a doubling of atmospheric carbon dioxide (the «climate sensitivity»).

This can be compared with some 200 W / m2 from direct sunshine, and about 6 W / m2 for what climate change models predict will happen if the atmospheric concentration of carbon dioxide doubles.

This translates out to about 41 trillion grams of carbon per year, three - quarters of which is attributed to the changing climate and one - quarter of which is attributed to increased atmospheric carbon dioxide concentration.

Ken Caldiera PhD, a professor at the Carnegie Institution Department of Global Ecology, studies carbon sequestration and stated that from the publicly available info about Calera's technology, it seems to go «in the wrong direction and will tend to increase and not decrease atmospheric CO2 content.»

Over the last 30 years, atmospheric levels of carbon dioxide increased by about 15 percent, from about 328 parts per million to about 372 parts per million.

Dull, et al, argue that the re-growth of Neotropical forests following the Columbian encounter led to terrestrial biospheric carbon sequestration on the order of 2 to 5 GtC, thereby contributing to the well - documented decrease in atmospheric C recorded in Antarctic ice cores from about 1500 through 1750.