Sentences with phrase «background concentrations»

«An increase by only a factor of 4 in global aerosol background concentration may be sufficient to reduce the surface temperature by as much as 3.5 ° K.»

In fact, when you get to very small amounts of CO2 (on the order of a few parts per million), the radiative forcing is much faster than logarithmic since you're opening up new opacity in the central 15 micron band where Earth is strongly emitting (it is for this reason methane changes are commonly cited as being «more powerful than CO2,» which is only true molecule - for - molecule in the modern atmosphere, as methane is starting off at much lower background concentrations.

Although background concentrations of gold in vegetation are typically less than 2 parts per billion (ppb), dried leaves from the trees growing above the ore deposit — but not those 200 meters away — had gold levels up to 80 ppb, says team member Mel Lintern, a geochemist at CSIRO's Earth Science and Resource Engineering division in Kensington, Australia.

Langmann, B., and S.E. Bauer, 2002: On the importance of reliable background concentrations of ozone for regional scale photochemical modelling.

«Their receptor is more sensitive than the background concentration,» Brand notes.

Interestingly, the logarithmic effect of CO2 on climate (adding 10 ppm to the atmosphere causes more warming when the background concentration is 300 ppm than when it is 400 ppm) managed to cancel out the increasing amounts of permafrost thaw.

Individual atoms or molecules may be lost or deposited to sinks such as the soil, the oceans and other waters, or vegetation and other biological systems, reducing the excess to background concentrations.

It was Callendar who first used meteorological data to construct a global temperature time series; who first established the background concentration level of atmospheric CO2 and identified an anthropogenic increase; and who was instrumental in bringing thirty years of advances in spectroscopy to bear on climate studies.