Sentences with phrase «concentrations reach high levels»

Only when lead concentrations reach high levels do they start to pose a threat to your health.

That research found that the highest death rates occurred the day after particulate concentrations reached their highest levels, though the levels were subtle enough to go unnoticed at the time.

Not exact matches

It seems reasonable to suggest that rather than simply maintaining a high work rate until the RPE does rise to reach near - maximal levels, the exercising athlete would instead reduce the work rate under conditions of elevated body temperature8 — 10 or depleted muscle glycogen concentrations, 13 giving rise to the possibility that the regulation of self - paced exercise may utilise the RPE as an important mediator of pacing strategy.

The plasma concentration of pethidine in the infant is almost as high as that in the mother, reaching a maximum after 2 - 3 hours, after which the level falls slowly.

National studies show that students who eat school breakfast are more likely to: reach higher levels of math achievement; score higher on tests; have better concentration, memory and alertness, improved attendance, behavior, and academic performance; and maintain a healthy weight

However, in ultra-rapid metabolizers, higher - than - expected concentrations of the active metabolite (morphine) may occur in breast milk, and potentially dangerous levels may be reached in breastfed infants.

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

The most dramatic effects were a nearly 2 mmHg rise in diastolic (the low number) blood pressure when the odor was rated an 8 compared with no odor, and a nearly 3 mmHg rise in systolic (the high number) blood pressure when hydrogen sulfide concentrations reached 10 parts per billion compared with no detectable level, the researchers reported last week in Environmental Health Perspectives.

This decision was supported by the conclusions of the NIAAA report, which stated: «Although elderly drinkers reach higher blood alcohol concentrations (BACs) with lower levels of consumption than the younger counterparts, their level of impairment at any given BAC level does not differ from that of younger drinkers.»

This is the most effective delivery method, because it allows plasma concentrations of the vitamin to reach levels high enough to potentially kill cancer cells and offer other benefits.

He says ``... concentrations of carbon dioxide in the atmosphere eventually would reach levels higher than in the Pliocene era, more than 2.5 million years ago...» Surely this is an error.

If we assume (as IPCC does) that human CO2 emissions are the single cause of increased atmospheric CO2 concentrations, the we could asymptotically reach an absolute highest level of atmospheric CO2 of around 1,030 ppmv WHEN ALL FOSSIL FUELS ARE 100 % USED UP.

So far as we skeptics are concerned, the best scenarios are those where CO2 reaches very high levels of concentration, just so long as this does not exceed 2000 ppmv.

The IPCC 2007 Fourth Assessment of climate change science concluded that large reductions in the emissions of greenhouse gases, principally CO2, are needed soon to slow the increase of atmospheric concentrations, and avoid reaching unacceptable levels.However, climate change is happening even faster than previously estimated; global CO2 emissions since 2000 have been higher than even the highest predictions, Arctic sea ice has been melting at rates much faster than predicted, and the rise in the sea level has become more rapid.

«Levels of greenhouse gases in the atmosphere reached new highs, and in the northern hemisphere spring 2015 the three - month global average concentration of CO2 crossed the 400 parts per million barrier for the first time.

«Climate science» as it is used by warmists implies adherence to a set of beliefs: (1) Increasing greenhouse gas concentrations will warm the Earth's surface and atmosphere; (2) Human production of CO2 is producing significant increases in CO2 concentration; (3) The rate of rise of temperature in the 20th and 21st centuries is unprecedented compared to the rates of change of temperature in the previous two millennia and this can only be due to rising greenhouse gas concentrations; (4) The climate of the 19th century was ideal and may be taken as a standard to compare against any current climate; (5) global climate models, while still not perfect, are good enough to indicate that continued use of fossil fuels at projected rates in the 21st century will cause the CO2 concentration to rise to a high level by 2100 (possibly 700 to 900 ppm); (6) The global average temperature under this condition will rise more than 3 °C from the late 19th century ideal; (7) The negative impact on humanity of such a rise will be enormous; (8) The only alternative to such a disaster is to immediately and sharply reduce CO2 emissions (reducing emissions in 2050 by 80 % compared to today's rate) and continue further reductions after 2050; (9) Even with such draconian CO2 reductions, the CO2 concentration is likely to reach at least 450 to 500 ppm by 2100 resulting in significant damage to humanity; (10) Such reductions in CO2 emissions are technically feasible and economically affordable while providing adequate energy to a growing world population that is increasingly industrializing.

Atmospheric CO2 concentrations have increased by almost 100 ppm in comparison to its preindustrial level, reaching 379 ppm in 2005, with mean annual growth rates in the 2000 — 2005 period that were higher than those in the 1990s.

It says greenhouse gases continued to climb, with concentrations of major gases − including carbon dioxide (CO2), methane and nitrous oxide − once again reaching historically high levels.

Trenberth still relates the effect from CO2 based on 100ppmv causing an increase of 0.6 °C but does not subtract the 0.5 °C of natural warming as recovery from the LIA that has nothing to do with CO2 emissions therefore producing an effect six times too high for the effect from increased CO2 Trenberth is not aware that CO2 is not increaseing at an accelerated rate as predicted by Hansen but at a near linear rate averaging 2.037 ppmv / year so by 2100 the concentration will not be as predicted by the IPCC as per scenario A1 but merely reach a level of 573.11 ppmv by 2100, This is only in the case that CO2 increase is maintained but this may not happen as the rate appears to be slowing down with the average rate for the past 5 years being lower than the rate for the past ten years.

This means that just by targeting these dirty old clunkers, badly tuned rust - buckets, and street racers, we could make a significant impact on air quality, especially in urban areas where the density of vehicles gets high enough for pollutant concentrations to reach dangerous levels.

Atmospheric CO2 concentrations have increased by almost 100 ppm in comparison to its preindustrial levels, reaching 379 ppm in 2005, with mean annual growth rates in the 2000 — 2005 period that were higher than those in the 1990s.