Sentences with phrase «significant warming of the climate system»

He rightly cited the solid scientific consensus showing significant warming of the climate system, with most global warming in recent decades mainly a result of human activity.

Not exact matches

Elevated trace GHG concentrations contributed an estimated positive forcing of approximately 1.7 — 2.3 W m - 2 (Table S5) in addition to that of CO2 and produced equilibrium climate system responses resulting in widespread significant warming, especially in the high latitudes (Figs. 3 and 4).

With the warming already committed in the climate system plus the additional warming expected from rising concentrations of greenhouse gases in the atmosphere, the Arctic will experience significant changes during this century even if greenhouse gas emissions are stabilized globally at a level lower than today's.

Subsidary question: as the ocean is quite a big part of the climate system, are it's temperature variations sufficiently constraint to corroborate the very interesting conclusion of Gavin's note: «It's interesting to note that significant solar forcing would have exactly the opposite effect (it would cause a warming)-- yet another reason to doubt that solar forcing is a significant factor in recent decades.»

For instance, the warming that began in the early 20th century (1925 - 1944) is consistent with natural variability of the climate system (including a generalized lack of significant volcanic activity, which has a cooling effect), solar forcing, and initial forcing from greenhouse gases.

It is also something quite different from «AGW», i.e. the scientifically based hypothesis that the observed LW energy absorption characteristics of CO2 (and other GHGs) would lead to a significant warming in our climate system with increased concentrations of these GHGs resulting from human GHG emissions (principally CO2), which is cited as the underlying scientific basis for the «CAGW» premise of IPCC.

First, Happer mentions statistical significance, but global surface temperature trends are rarely if ever statistically significant (at a 95 % confidence level) over periods as short as a decade, even in the presence of an underlying long - term warming trend, because of the natural variability and noise in the climate system.

I can certainly understand why those who do not have as clear an understanding of the climate system as Jim Hansen does would want to be more ambivalent with respect to advocating action to counteract global warming since, this has very significant economic implications.

But the lack of statistically significant results and, more important, the absence of evidence pointing to a smoking gun — a physical mechanism in the climate system that ties Arctic changes to extreme events — has left many top climate researchers unconvinced that rapid Arctic warming is a major player in causing extreme weather events outside of the Arctic itself.

Hansen and Sato (2012), using paleoclimate data rather than models of recent and expected climate change, warn that «goals of limiting human made warming to 2 °C and CO2 to 450 ppm are prescriptions for disaster» because significant tipping points — where significant elements of the climate system move from one discrete state to another — will be crossed.

Moreover, at a time when we should be making massive cuts in the emissions of greenhouse gases into the atmosphere in order to reduce the threat posed by climate change, the food system is lengthening its supply chains and increasing emissions to the point where it is a significant contributor to global warming.

However, the climate system is not linear, and if there are significant negative feedbacks to increased radiative forcing, then a significant portion of the recent warming could've been caused by natural variability if the corresponding variability went up with temperature.