Sentences with phrase «increased isotope ratios»

cooler temperatures are associated with increased isotope ratios).

Not exact matches

The second factor was an increase in the weathering of the Appalachian rocks between 462 and 454 million years ago, which is indicated by changes in strontium isotope ratios in Ordovician oceanic rocks (Geology, DOI: 10.1130 / g30152a.1).

Initial SAM results show an increase of 5 percent in heavier isotopes of carbon in the atmospheric carbon dioxide compared to estimates of the isotopic ratios present when Mars formed.

It may be a change activity in shallow water or surface sediment organisms producing more methane, rather than increased melting in deep sediments — isotope ratios ought to help clarify that.

Isotope ratios of carbon are one very strong line of evidence to show that the increase in CO2 comes from the burning of fossil fuels.

The change to the 12C: 13C isotope ratio of atmospheric CO2 is in the direction expected if the recent increase in atmospheric CO2 concentration were caused by the anthropogenic emission of CO2.

The fact in point (5) indicates that most of the change to the 12C: 13C isotope ratio of atmospheric CO2 and most of the recent increase in atmospheric CO2 concentration was caused by some unknown, natural (i.e. non-anthropogenic) effect.

As for the alleged irrefutable evidence that people caused the last century's CO2 increase, the «smoking gun» invoked by one of my critics, Dr. Michael Mann, and his fellow fearmongers at realclimate.com, the claim is based on the idea that the normal ratio of heavy to light carbon — that is, the carbon - 13 isotope to the lighter carbon - 12 isotope, is roughly 1 to 90 in the atmosphere, but in plants there's a 2 percent lower C13 / C12 ratio.

Richard S Courtney (00:08:00): The change to the 12C: 13C isotope ratio of atmospheric CO2 is in the direction expected if the recent increase in atmospheric CO2 concentration were caused by the anthropogenic emission of CO2.

As Pat notes, several different isotope ratios lead to the conclusion that humans are largely responsible for the increase.

It is possible that both the effects noted in points 7 and 8 contributed to the change to the 12C: 13C isotope ratio of atmospheric CO2 and to the recent increase in atmospheric CO2 concentration.

The group also reveals that the greatest change in nitrogen isotope ratios occurred between 1950 and 1980, following a rapid increase in fossil fuel emissions.

As such, assigning anthropogenic causation to C13 / C12 Isotope ratios is highly suspect, and furthermore Wei et al. only found increasing trends «over the past 60 years».

This matches the increase, the carbon isotope ratios, the declining oxygen etc etc..

Even allowing for the «uncertainty monster», I think the question that humans are causing the increase in CO2 is an open - and - shut case, but it's the isotope ratios that nails it.

But there's virtually no way to explain the change in the isotope ratio, other than by an increase in CO2 originating from the burning of fossil fuels.

But I think Ferdinand Engelbeen (just do a search for his name here or Climateaudit) would disagree about the source of the current CO2 increase — his isotope - ratio arguments are pretty convincing that they're from fossil - fuel combustion.

«If the increases in atmospheric CO2 are being driven by fossil fuel emissions then changes in the isotope ratio would be expected to occur first in the Northern Hemisphere and then move to the Southern Hemisphere.

Also, the carbon isotope ratios are supposed to show that the increase is anthropogenic (from using burning «old carbon», less C14 or deduced by C13 / C12 ratios, etc..)

It's usually taken to be the fact that as carbon dioxide concentrations in the atmosphere increase, the 1 per cent of CO2 that's the heavier carbon isotope ratio c13 declines in proportion.

Discussions of isotope ratios and uptake and emission of CO2 by all the various and sundry physical and biological processes are distractions to the simplest and most compelling line of evidence that the increase in atmospheric CO2 concentrations is primarily anthropogenic — to wit, comparing the expected concentration increase based on anthropogenic emission rates with the actual increase over a given period of time.

This does not favour the continuous increase of CO2 from the use of fossil fuels as the source of isotope ratio changes.

Regarding the link between fossil - fuel burning and the CO2 increase, there's the changing ratios carbon isotope ratios in the atmosphere and the decreasing oxygen concentration.

Paleo temperatures from oxygen isotope ratios from the greenland ice cores show that a temperature increase of 0.7 °C will not bring the current temperature up to the level of the Medieval Warm Period let alone the Roman optimum and the MInoan Warm period which were both warmer than the medieval warm period.

This would throw off the isotope ratios and could be happening due to the increase in atmospheric CO2.

«The rapid decrease in carbon isotope ratios in the top panel is indicative of a large increase in atmospheric greenhouse gases CO2 and CH4 that was coincident with an approximately 5 °C global warming (centre panel).»