Sentences with phrase «forcing by greenhouse gases»

The total radiative forcing by greenhouse gases is around 3 W / m2, with which we have «committed» the planet to warm up by 2.4 °C (1.6 - 3.6 °C), according to a climate sensitivity of 3 °C (2 - 4.5 °C) for a doubling of CO2.

«There is evidence of an emerging pattern of climate response to forcing by greenhouse gases and sulfate aerosols... from the geographical, seasonal and vertical patterns of temperature change... These results point toward a human influence on global climate.»

The global surface temperature increase since about 1860 corresponds to a recovery from the Little Ice Age, modulated by natural ocean and atmosphere cycles, without need for additional forcing by greenhouse gases.

Your claims of radiative forcing by greenhouse gases is wildly exaggerated.

For forcing by greenhouse gases (GHGs) only, we show that there is a greater than 90 % probability that the expected warming over 1950 — 2005 is larger than the total amount (not just «most») of the observed warming.

It's painfully easy to paint oneself logically into a corner by arguing that either (i) vigorous natural variability caused 20th century climate change, but the climate is insensitive to radiative forcing by greenhouse gases; or (ii) the climate is very sensitive to greenhouse gases, but we still are able to attribute details of inter-decadal wiggles in the global mean temperature to a specific forcing cause.

and 1998 snippets Methane now contributes about 20 % to the increased direct radiative forcing by greenhouse gases compared to preindustrial times [Shine et al., 1995] Oxidation of CH4 in the troposphere produces carbon monoxide (CO), can lead production of ozone (03), and involves atmospheric oxidant, the hydroxyl radical (OH).

Vinnikov et al. (1999) used the aforementioned GFDL and Hadley Centre climate models, forced by greenhouse gases and sulfate aerosols, to project how Arctic sea ice extent would change in the future.

The main source of skill in temperature is the trend, which is primarily forced by greenhouse gases and aerosols.

Schematic diagram of human - made climate forcings by greenhouse gases, aerosols, and their net effect.

We argue that this is the long - term anthropogenic trend, forced by greenhouse gas increases offset by tropospheric aerosol cooling, which also increased along with industrialization.

Not exact matches

While the new President can certainly help reduce industry costs by, among other things, canceling Obama's Clean Energy Plan, which would force power plants to capture more greenhouse gases, it is not clear if this will be enough.

Its contribution to heating forcing (caused by greenhouse gases, ground - level ozone and «black carbon» [4]-RRB- is 12 % on average.

The researchers [3] quantified China's current contribution to global «radiative forcing» (the imbalance, of human origin, of our planet's radiation budget), by differentiating between the contributions of long - life greenhouse gases, the ozone and its precursors, as well as aerosols.

Professor Sybren said: «It can be excluded, however, that this hiatus period was solely caused by changes in atmospheric forcing, either due to volcanic eruptions, more aerosols emissions in Asia, or reduced greenhouse gas emissions.

«While this increase is similar to that produced by greenhouse gases, it may well turn round with the 11 - year cycle so it can't be used to imply any long - term forcing.»

In the study, researchers analyzed a series of transient Coupled General Circulation Model simulations forced by changes in greenhouse gases, orbital forcing, meltwater discharge and the ice - sheet history throughout the past 21,000 years.

But our main point does not depend on that and is robust: with any model and any reasonable data - derived forcing, the observed 20th Century warming trend can only be explained by anthropogenic greenhouse gases, while other factors can explain the shorter - term variations around this trend.

So to adjust from 1750 - 2000 to 1850 - 2000 forcings, one must remove 0.215 W / m ² and also remove the -0.164 W / m ² aerosol forcing, multiplying the latter by it's impact relative to that of well - mixed greenhouse gases (~ 1.5) that gives about -0.25 W / m ².

[Response: Well, something like a circulation changed forced by the NAO pattern (which may in turn be affected by greenhouse gases) might cause an increase in European air temperatures, which in turn would allow low level moisture to increase if there is enough moisture supply, which would then constitute an amplification of a signal driven remotely.

To be added, other greenhouse gas forcings with their feedbacks and internal oscillations which may be — or not — enhanced by the primary forcings.

(2) The largest positive radiative forcing — by far — has been the one due to long - lived greenhouse gases, most notably, CO2.

GCAM uses market forces to reach a specified greenhouse gas emission target by allowing global economics to put a price on carbon.

If one accepts Ruddiman's hypothesis, one implicitly agrees that: i) CO2 and CH4 can be affected by human activity, ii) greenhouse gases have a significant forcing role, and iii) climate sensitivity is in the ballpark of mainstream estimates.

Shindell, D.T., R.L. Miller, G.A. Schmidt, and L. Pandolfo, 1999: Simulation of recent northern winter climate trends by greenhouse - gas forcing.

... The Earth's atmospheric methane concentration has increased by about 150 % since 1750, and it accounts for 20 % of the total radiative forcing from all of the long - lived and globally mixed greenhouse gases (these gases don't include water vapor which is by far the largest component of the greenhouse effect).

But as far as I can tell, most sceptics don't flat out deny greenhouse gas warming, but they incorporate their «extra» forcing by assuming a lower climate sensitivity.

Two decades have been spent trying, and failing, to force developed countries to slash greenhouse gas pollution levels by particular amounts within specified timeframes under international law.

Courtillot et al. commit the «flat Earth» error from which our article draws its name: they give a misleading impression of the comparison of forcing by solar variability relative to greenhouse gas forcing by failing to take into account the Earth's spherical geometry and albedo.

There is medium confidence that the GMST trend difference between models and observations during 1998 — 2012 is to a substantial degree caused by internal variability, with possible contributions from forcing error and some CMIP5 models overestimating the response to increasing greenhouse - gas forcing.»

Most studies consider a range of anthropogenic forcing factors, including greenhouse gases and sulphate aerosol forcing, sometimes directly including the indirect forcing effect, such as Knutti et al. (2002, 2003), and sometimes indirectly accounting for the indirect effect by using a wide range of direct forcing (e.g., Andronova and Schlesinger, 2001; Forest et al., 2002, 2006).

The changes in forcing brought about by these greenhouse gas changes (including water vapor) are a feedback on the initial forcing of the proximate cause.

Using Mg / Ca paleothermometry from the planktonic foraminifera Globigerinoides ruber from the past 500 k.y. at Ocean Drilling Program (ODP) Site 871 in the western Pacific warm pool, we estimate the tropical Pacific climate sensitivity parameter (λ) to be 0.94 — 1.06 °C (W m − 2) − 1, higher than that predicted by model simulations of the Last Glacial Maximum or by models of doubled greenhouse gas concentration forcing.

Note that while results from fingerprint detection approaches will be affected by uncertainty in separation between greenhouse gas and aerosol forcing, the resulting uncertainty in estimates of the near - surface temperature response to greenhouse gas forcing is relatively small (Sections 9.2.3 and 9.4.1.4).

The cooling seen in the lower stratospheric MSU 4 record is indeed mostly due to ozone depletion (interrupted by a couple of big volcanoes), but the cooling further up is indeed consistent with the expected forcings from greenhouse gases.

«The idea behind this index is to determine what the temperature increase will be by the decade when anthropogenic greenhouse gas forcing — which is dominated by CO2 — doubles what it was in about 1880,» Christy said.

«It is thus extremely likely (> 95 % probability) that the greenhouse gas induced warming since the mid-twentieth century was larger than the observed rise in global average temperatures, and extremely likely that anthropogenic forcings were by far the dominant cause of warming.

Forcings, measured in W / m2 averaged over the globe, are imposed perturbations of Earth's energy balance caused by changing forcing agents such as solar irradiance and human - made greenhouse gases (GHGs).

In addition, both internal variability and aerosol forcing are likely to affect tropical storms in large part though changes in ocean temperature gradients (thereby changing ITCZ position and vertical shear), while greenhouse gases likely exert their influence by more uniformly changing ocean and tropospheric temperatures, so the physics of the problem may suggest this decomposition as more natural as well.

These phenomena — sun spots, a slightly different earth orbit, a decrease in volcanic activity — intermittently warmed the region through increased radiative forcing, and recently have been joined by a new force: greenhouse gases.

So isn't not fair to state that we see increase in TC power in recent decades, and that this is expected giving rising SST, which are driven by greenhouse gas forcing.

It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together.

While the local, seasonal climate forcing by the Milankovitch cycles is large (of the order 30 W / m2), the net forcing provided by Milankovitch is close to zero in the global mean, requiring other radiative terms (like albedo or greenhouse gas anomalies) to force global - mean temperature change.

However, such model studies can not provide definite answers, as there is a range of possible model outcomes because the solar forcing is just one of several forcings (e.g. aerosols, greenhouse gases, land surface) that are not well - constrained by observations.

AR5: It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together.

A task force assembled by the American Psychological Association hopes to spur more research on the role of the human mind in shaping the behaviors resulting in rising greenhouse - gas emissions as well as on traits that can impede an effective response to global warming and similar slow - building environmental risks.

In fact, these past climate changes allow us to learn how sensitive the earth's climate system is to the known radiative forcing that we are producing by increasing the levels of greenhouse gases in the atmosphere.

At the last glacial maximum (20,000 yrs ago), forcings by ice sheets, vegetation, greenhouse gases and dust loading are estimated to be around -7 W / m2, and that sustained a climate 5 to 6 degrees cooler than present.

It's only a fraction of the heat that we emit directly into the atmosphere by primary energy consumption (which is also negligible compared to greenhouse gases) and compensates for a forcing of roughly 10 mW / m ².

Using Mg / Ca paleothermometry from the planktonic foraminifera Globigerinoides ruber from the past 500 k.y. at Ocean Drilling Program (ODP) Site 871 in the western Pacific warm pool, we estimate the tropical Pacific climate sensitivity parameter (λ) to be 0.94 — 1.06 °C (W m − 2) − 1, higher than that predicted by model simulations of the Last Glacial Maximum or by models of doubled greenhouse gas concentration forcing.