Sentences with phrase «co2 levels were at»

On average, sea levels were between 50 and 82 feet higher the last time CO2 levels were at 400ppm.

It did so when CO2 levels were at least 800ppm.

Corals evolved during the Cambrian era when atmospheric CO2 levels were at 6,000 - 7,000 ppm, around 4,000 percent or 20 times higher than today's «CO2 - starved» environment of 400 ppm.

And CO2 is not the cause, as determined by scientists for the 300 - year drought that ended the Bronze Age (CO2 levels were at pre - industrial / consumer levels).

CO2 levels were at about 400 ppm.

Empirical evidence tells us that the last time CO2 levels were at 400 ppm, the oceans were considerably higher, perhaps in the neighborhood of 85 feet.

By the mid-18th century, CO2 levels were at 280 ppm.

The problems with associating sensitivity with a temperature in 2100 are twofold: first, at the time we reach CO2 doubling, the temperature will lag behind the equilibrium value due to thermal inertia, especially in the ocean (thought experiment — doubling CO2 today will not cause an instant 3C jump in temperatures, any more than turning your oven on heats it instantly to 450F), and secondly, the CO2 level we are at in 2100 depends on what we do between now and then anyway, and it may more than double, or not.

tallbloke (05:52:23): According to the Scotese et al graph posted by Anthony on the Hansen thread, the temperature was about 10C higher when the co2 level was at 8000ppm 550M years ago.

According to the Scotese et al graph posted by Anthony on the Hansen thread, the temperature was about 10C higher when the co2 level was at 8000ppm 550M years ago.

AND temperatures start climibing when CO2 levels are at their LOWEST, and start falling when CO2 levels are at their HIGHEST, all of which which firmly erases ANY notion that CO2 «drives» temperature.

Not exact matches

Allen notes that there are lots of consumer - friendly carbon dioxide detectors on the market, adding that the research found that people performed best at CO2 levels of 500 to 600 ppm.

at risk of not helping, the AR4 WG3 carbon price range of 30 - 50 USD is based on stabilizing CO2 at 450ppm, a level more recent work has determined to be very dangerous.

Reached by phone and asked of the possibility that CO2 levels aren't at 400, a spokesman for the agency laughed.

At that time, CO2 levels are thought to have been close to current levels — around 390 parts per million — but global temperatures were warmer.

When the fish grew up in fresh water and seawater with high concentrations of CO2, they lost weight at double the rate of fish that were only exposed to salt water with higher CO2 levels.

Part of the reason it took longer to recognize the impact of CO2 is because adult fish tend to be more capable of handling higher levels of acidity, said Colin Brauner, a zoology professor at UBC and co-author of the study.

Ou and her colleagues at UBC created an experiment to test how fish were responding not only to ambient CO2 concentrations but also to acidity levels expected by 2100.

A new climate change modeling tool developed by scientists at Indiana University, Princeton University and the National Oceanographic and Atmospheric Administration finds that carbon dioxide removal from the atmosphere owing to greater plant growth from rising CO2 levels will be partially offset by changes in the activity of soil microbes that derive their energy from plant root growth.

In the report, an international team of climate scientists warns policy - makers that levels of carbon dioxide in the atmosphere are at the extreme end of predictions made only in 2007, and that natural CO2 sinks such as oceans are becoming saturated.

At a global level, the excess of atmospheric CO2 is absorbed by ocean waters and it causes changes in water chemistry (pH decrease or ocean acidification).

So, we're talking about this period 3.5 million years ago, this is the middle Pleistocene, and that's where the CO2 concentrations were round about 400 ppm; and if we want to look at CO2 concentrations considerably higher than that, we're going to go much deeper in time, and then we're really going into periods where sea level was even higher.

In this study in Timothy grass, researchers led by environmental health scientist Christine Rogers of the UMass Amherst School of Public Health and Health Sciences (SPHHS) determined the interactive effects of CO2 and ozone at projected higher levels on pollen production and concentrations of a Timothy grass pollen protein that is a major human allergen.

Among the most pressing questions is how fish react to rising levels of CO2, said Tom Bigford, policy director at the American Fisheries Society.

Climate models suggest that widespread glaciations couldn't take place at that time unless CO2 levels dropped to about eight times what they are at present, says Tim Lenton, an earth scientist at the University of Exeter in the United Kingdom.

CO2 levels are projected to be 2.5 times higher in the oceans by the end of this century, which is causing the ocean to acidify at a rate unprecedented for 300 million years.

The IPCC has mapped out possible futures in which CO2 levels would be stabilised at anything from current levels to 1.6 trillion tonnes, to be reached at various times over the next 200 years.

The amount of carbon dioxide (CO2) in the air is now at its highest level in human history, largely because of coal - burning power plants and vehicle emissions.

The ice core data also shows that CO2 and methane levels have been remarkably stable in Antarctica — varying between 300 ppm and 180 ppm — over that entire period and that shifts in levels of these gases took at least 800 years, compared to the roughly 100 years in which humans have increased atmospheric CO2 levels to their present high.

That amounts to about 50 percent more CO2 than was in ambient air at the experiment's beginning, and double preindustrial levels.

In climate science, for example, where we don't need an elaborate climate model to understand the basic physics and chemistry of greenhouse gases, so at some level the fact that increased CO2 warms the planet is a consequence of very basic physics and chemistry.

Once atmospheric CO2 levels rise and plants begins to photosynthesise at a higher rate, the fungi may not be able to provide nitrates quickly enough to meet the plants» demands.

When the Kyoto protocol was drawn up in 1997, the CO2 level had reached at 368 ppm.

«This does not necessarily mean that a similar response would happen in the future with increasing CO2 levels, since the boundary conditions are different from the ice age,» added by Professor Gerrit Lohmann, leader of the Paleoclimate Dynamics group at the Alfred Wegener Institute.

Looking at strains of the plankton under varying CO2 levels, researchers found that while some plankton had difficulties forming their shells when the water was more acidic, others did not, causing researchers to speculate that the plankton might be able to use another form of calcium to substitute in shell making.

Moreover, finding a self - contained lake of carbon dioxide at a relatively shallow 4,600 feet below sea level «is highly suggestive that if you went down a further 4,900 feet you could actually inject liquid CO2 and it would be quite stable,» says Ken Nealson, a geobiologist at the University of Southern California.

Before the industrial age, the CO2 level was steady at around 280 parts per million.

The researchers used predictions of the amount of CO2 that would be in the atmosphere at the end of this century to set the CO2 levels in these last five bags.

Co2 is.04 % of all green house gas and increased levels are the result of the sun heating up, as evidence points to the other planets and moons heating up at the same rate.

Published in the journal Oecologia, the study is the first to show that even freshwater fish which only spend a small portion of their lifecycle in the ocean are likely to be seriously affected under the higher CO2 levels expected at the end of the century.

There is hope, however, as CO2 from burning fossil fuels and other human activities appears to have leveled off in 2015 at roughly 40 billion metric tons of CO2 liberated into the atmosphere.

«The atmospheric and oceanic CO2 increase is being driven by the burning of fossil fuels,» says Pieter Tans, a senior scientist at the National Oceanic and Atmospheric Administration's Earth System Research Laboratory, who leads the U.S. government effort to monitor global greenhouse gas levels.

Their results showed that changes in key water - stress variables are strongly modified by vegetation physiological effects in response to increased CO2 at the leaf level, illustrating how deeply the physiological effects due to increasing atmospheric CO2 impact the water cycle.

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.

Using the samples, Quinton analyzed them for chemical clues that can be related to CO2 levels at specific time periods.

Numerous groups around the world have been conducting experiments in which plots of land are supplied with enhanced CO2, while comparable nearby plots remain at normal levels.

It's also possible that the growth spurt is partly due to a rise in CO2 levels, which may «fertilise» forests, says Iain Robertson of the School of the Environment and Society at Swansea University, UK.

The point they make is that future climate change due to inertia has been assessed by keeping CO2 concentrations at some predetermined level, that is, that there will be no future increase in human input of CO2 into the atmosphere.

This is the warming you get if we keep CO2 (and other GHG and pollutant levels) constant at today's values.

Recent findings, however, suggest that the rate at which levels of CO2 are increasing today far exceeds that of the PETM era.