Sentences with phrase «significant period of warming»

There was a significant period of warming during the last 20 years of the 20th century, followed by a significant slowdown in warming during the 21st.

Not exact matches

There is no evidence for significant increase of CO2 in the medieval warm period, nor for a significant decrease at the time of the subsequent little ice age.

The researchers detected a «significant regional flux» of methane, a greenhouse gas with about 30 times the warming potential of carbon dioxide over a 100 - year period, coming from an area of gas wells in southwestern Pennsylvania.

«Using a numerical climate model we found that sulfate reductions over Europe between 1980 and 2005 could explain a significant fraction of the amplified warming in the Arctic region during that period due to changes in long - range transport, atmospheric winds and ocean currents.

The most significant criticism is that Soon and Baliunas do not present their data quantitatively — instead they merely categorize the work of others primarily into one of two sets: either supporting or not supporting their particular definitions of a Medieval Warming Period or Little Ice Age.

U.S. Data Since 1895 Fail To Show Warming Trend LINK WASHINGTON, Jan. 25 — After examining climate data extending back nearly 100 years, a team of Government scientists has concluded that there has been no significant change in average temperatures or rainfall in the United States over that entire period.

Two examples of climate extremes include periods of intense warm or cool temperatures and significant wet or dry spells across seasons.

We assess the heat content change from both of the long time series (0 to 700 m layer and the 1961 to 2003 period) to be 8.11 ± 0.74 × 1022 J, corresponding to an average warming of 0.1 °C or 0.14 ± 0.04 W m — 2, and conclude that the available heat content estimates from 1961 to 2003 show a significant increasing trend in ocean heat content.

Amplitude and Duration: The most significant events are terminations of the glacial period and rapid onset of global warming of the interglacial period.

That means that the chance of a «not statistically significant warming» in any given short period is high.

Given that these two periods also were those of the most significant warming in our atmosphere.

The fact remains that the rate of warming in the early 20th century is comparable to that in the late 20th century whether you look at the Arctic in isolation or the globe as a whole and since CO2 levels were markedly different in the 2 periods there must be another significant factor.

I often hear nuclear advocates proclaiming that «nuclear is THE solution to global warming» and that «no one can be serious about dealing with global warming if they don't support expanded use of nuclear power» but I have never heard any nuclear advocate lay out a plan showing how many nuclear power plants would have to be built in what period of time to have a significant impact on GHG emissions.

Looking at the last decades, of all possible 15 - year periods around half had significant warming and the other half didn't.

Because the long - term warming trends are highly significant relative to our estimates of the magnitude of natural variability, the current decadal period of stable global mean temperature does nothing to alter a fundamental conclusion from the AR4: warming has unequivocally been observed and documented.

Actually, there is some interesting work being done by Matt Huber of Purdue, following up on some earlier ideas of Emanuel's, suggesting that the role of TCs in transporting heat from equator towards the poles may be more significant than previously thought — it also allows for some interesting, though admittedly somewhat exotic, mechanisms for explaining the «cool tropics paradox» and «equable climate problem» of the early Paleogene and Cretaceous periods, i.e. the problem of how to make the higher latitudes warm without warming the tropics much, something that appears to have happened during some past warm epochs in Earth's history.

Just a quick note to say that the paleoclimate data for earlier warm periods 125,000 years ago and even 8 - 10,000 years ago in northern Alaska (paleoclimate warmer than now, [from] different forcings) document the northward advance of the treeline from Nome to Barrow, Alaska, and the Canadian border at different times of change in Earth's orbital parameters (without a significant change in CO2).

In fact previous climate warming after the last ice age did have significant negative impacts on early human settlements (evidence of periods of significant and rapid regional sea level rise).

«A significant share of the warming we saw from 1980 to 2000 and at earlier periods in the 20th Century was due to these cycles â $ «perhaps as much as 50 per cent.

Research indicates that the Arctic had substantially less sea ice during this period compared to present Current desert regions of Central Asia were extensively forested due to higher rainfall, and the warm temperate forest belts in China and Japan were extended northwards West African sediments additionally record the «African Humid Period», an interval between 16,000 and 6,000 years ago when Africa was much wetter due to a strengthening of the African monsoon While there do not appear to have been significant temperature changes at most low latitude sites, other climate changes have been repperiod compared to present Current desert regions of Central Asia were extensively forested due to higher rainfall, and the warm temperate forest belts in China and Japan were extended northwards West African sediments additionally record the «African Humid Period», an interval between 16,000 and 6,000 years ago when Africa was much wetter due to a strengthening of the African monsoon While there do not appear to have been significant temperature changes at most low latitude sites, other climate changes have been repPeriod», an interval between 16,000 and 6,000 years ago when Africa was much wetter due to a strengthening of the African monsoon While there do not appear to have been significant temperature changes at most low latitude sites, other climate changes have been reported.

A main control on atmospheric CO2 appears to be the ocean surface temperature, and remains a possibility that a significant part of the overall increase of atmospheric CO2 since at least 1958 (start of Mauna Loa observations) simply relflects the gradual warming of the oceans as a result of the prolonged period of high solar activity since 1920 (Solanki et al., 2004).

All evidence suggests that significant climate changes like the LIA, and the Medieval Warm Period that preceded it, are the result of significant changes in solar activity.

Interestingly, the paper «Climate Trends and Global food production since 1980» (Lobell, Schlenker, Costa - Roberts, in Sciencexpress, 5 May, Science 1204531) confirms my finding of the absence of climate change in the USA: «A notable exception to the [global] warming pattern is the United States, which produces c. 40 % of global maize and soybean and experienced a slight cooling over the period... the country with largest overall share of crop production (United States) showed no [adverse] effect due to the lack of significant climate trends».

U.S. Data Since 1895 Fail To Show Warming Trend LINK WASHINGTON, Jan. 25 — After examining climate data extending back nearly 100 years, a team of Government scientists has concluded that there has been no significant change in average temperatures or rainfall in the United States over that entire period.

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 note that an analysis of ocean data has shown no significant warming during the period of 1978 -2000.

«If the surface temperature resumed the warming rate that we observed from, say 1977 through 1998, we would still go close to a quarter of a century without significant net warming because there's such a long flat period built into the record now.

Using a large volume of 126 proxy temperature records from the Northern Hemisphere, they found (1) a clearly discernible Medieval Warm Period (MWP)(950-1150) and Little Ice Age (LIA)(1450 - 1850), (2) «likely unprecedented» modern temperatures (relative to the last 1,000 years), as well as a (3) «significant» link between the high temperatures of the MWP and recent times and the high solar activity that characterized both periods (the Medieval Maximum and the Modern Grand Maximum).

This is particularly significant because this is the period of the large recent warming that people claim is due to CO2.

So if the second half of the 20th century had the highest average absolute levels of solar activity for «several thousand years» (Solanki) and at least 350 + years (Lean), then this could well have been a significant cause of late 20th century warming (building in all the «time lags» one might envision), despite the fact that the absolute level of solar activity was declining over this period.

-- The same goes for the earlier multi-decadal period of slight cooling (~ 1940 - 1970) and especially for the early 20thC period of rapid warming (1910 - 1940), which occurred prior to significant human GHG emissions.

We assess the heat content change from both of the long time series (0 to 700 m layer and the 1961 to 2003 period) to be 8.11 ± 0.74 × 1022 J, corresponding to an average warming of 0.1 °C or 0.14 ± 0.04 W m — 2, and conclude that the available heat content estimates from 1961 to 2003 show a significant increasing trend in ocean heat content.

The lack of a statistically significant warming trend in GMST does not mean that the planet isn't warming, firstly because GMST doesn't include the warming of the oceans (see many posts on ocean heat content) and secondly because a lack of a statistically significant warming trend doesn't mean that it isn't warming, just that it isn't warming at a sufficiently high rate to rule out the possibility of there being no warming over that period.

Well the devil is in the details — further, if we are to be convinced by the AR5 attribution of what is essentially a strong warming period of 30 years, then unexplained periods temperature variability of 30 years are significant.

From 1910 to 1940, and from 1970 et 2000 (2 periods of 30 years that are significant in terms of climate evolution), we have observed roughly the same warming of about de 0.5 °C (respectively 0.47 et 0.48 °C), whereas:

A general acknowledgement that it has not warmed significantly over a period of over a decade, despite the fact that human CO2 emissions have continued unabated, but that this trend is too short to be statistically significant.

Any warming observed prior to WWII is indicative of «global warming» (GW), but (since there were no significant human GHG emissions yet) is counterindicative of anthropogenic greenhouse warming (AGW), since something other than human GHGs caused it, raising the question: if non GH warming caused this warming, could it not also have caused the most recent extended warming period?

ie, a look at the actual temperature in the central england data set from the 1600's, would give a null hypothesis for any significant observable human AGW signature (ie a low % of AGW) as there only appear to be a gradual warming trend from a period known as the «little ice age».

For longer time periods appropriate to the assessment of trends, however, global temperatures have experienced significant warming for all seasons except winter, when cooling trends exist instead across large stretches of eastern North America and northern Eurasia.

JTFs: The IPCC attribution statement is limited to the period since 1950 precisely because studies fail to attribute a significant amount of warming before then to anthropogenic forcing.

There was no statistically significant warming from 1978 - 1992, or from 1979 - 1993, or 1980 - 1994, or 1981 - 1995, or 1995 - 2009, or any of the other 14 year periods.

Increases in GrIS melt and runoff during this past century warm period must have been significant and were probably even larger than that of the most recent last decade (1995 - 2006).»

Identifying icebergs as a significant source of bioavailable Fe may shed new light on how the oceans respond to periods of atmospheric warming.»

The combination of warming over that period, the increase in CO2, and a probable anthropogenic isotope signature to that increase make a century long significant causal contribution plausible.

Based on previously reported analysis of the observations and modelling studies this is neither inconsistent with a warming planet nor unexpected; and computation of global temperature trends over longer periods does exhibit statistically significant warming.

Whether there has been «significant warming» over some time period is a matter of observation, not statistical analysis.

Jones answered honestly, if a bit clumsily, that the data period since 1995 is marginally too short to derive a statistically significant trend, a response which was headlined by the Daily Mail as «Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995?»

An analysis of satellite temperature dataset, through February 2014, identifies only two 5 - year periods having significant warming and five periods that exhibit either zero warming or cooling... the consensus experts» predicted reaction, by the climate, to a surge of human CO2 emissions is not supported by empirical evidence

I support the position of it being «not yet definitive» that CO2 has had any significant impact on warming over the period Monckton of Brenchley mentioned.

The inclusion of the very warm 1998 El Nino year at the end (or start) of either of those two periods only has a significant effect on the trend over the shorter period.