Sentences with phrase «urban warming trends»

Instead of eliminating the urbanization effects, these wrong - way corrections makes the urban warming trends steeper.

«Wavelet analysis shows that this relative urban warming trend was primarily manifested in the form of multi - decadal and interseasonal cycles that are likely attributable to gradual increased winter heating in Ottawa (heat island effects) associated with population growth.

As we discussed above, for almost all of NASA's adjustments to remove an urban warming trend there is an equivalent adjustment to remove an «urban cooling» trend from another station.

Not exact matches

The locations of weather stations, changes in instruments, the siting of weather stations in warmer urban areas, changes in land cover and other issues have all been cited as issues affecting the temperature trends often used to show that our planet is in fact warming.

The warming trend is the same in rural and urban areas, measured by thermometers and satellites, and by natural thermometers.

Bikes vs. Cars (Unrated) Eco-documentary advocating the adoption of bicycles over autos as the primary form of urban transportation in order to reverse the global warming trend.

Future topics that will be discussed include: climate sensitivity, sea level rise, urban heat island - effects, the value of comprehensive climate models, ocean heat storage, and the warming trend over the past few decades.

After much debate the issue was pretty much settled, in terms of figuring out how to compensate for the urban effect and detecting a warming trend anyway, by 1990.

There are quite a few reasons to believe that the surface temperature record — which shows a warming of approximately 0.6 ° -0.8 °C over the last century (depending on precisely how the warming trend is defined)-- is essentially uncontaminated by the effects of urban growth and the Urban Heat Island (UHI) efurban growth and the Urban Heat Island (UHI) efUrban Heat Island (UHI) effect.

[1] Controversy has persisted over the influence of urban warming on reported large - scale surface - air temperature trends.

But for the moment, twin trends are exacerbating the threat: the urban rush in developing countries, in which millions of poor people are settling on fragile slopes and floodplains, and rising odds of rain falling in dangerous downpours in a warming world.

Generally, the remaining uncorrected effect from urban heat islands is now believed to be less than 0.1 C, and in some parts of the world it may be more than fully compensated for by other changes in measurement methods.4 Nevertheless, this remains an important source of uncertainty.The warming trend observed over the past century is too large to be easily dismissed as a consequence of measurement errors.

However, again, the urban stations also show an underlying warming trend, which substantially changes the context of the trends.

Even the most pronounced warming, evident from the cities of Hobart and Melbourne, is within what could be considered natural — though the trends shown here are likely to be artificially exaggerated by the method of measuring temperature since 1996 ** (electronic probes) and the urban heat island (UHI) effect.

I see you wrote 6 paragraphs about your supposed climate «skepticism» arising from the urban heat island effect, but I see not a single word of explanation about why the UHI effect would turn a non-warming trend into a warming trend.

The first part of the adjustment removes a warming trend from the urban record, as we would expect.

The study team found that the trends match well; the «opposite» of what one should expect «if the urban heat island effect was adding anomalous warming to the record.»

Although he doesn't actually come out and say it, Evans suggests that the global warming trend in the surface temperature record is an artifact caused by the urban heat island (UHI) effect:

Since you can not explain why correction for urban heating creates a warmer trend — and not a cooler trend!

and b) the urban heat effect (see recent paper by McKitrick), the consensus on a warming trend would appear differently; add to that the fact that some analysis show that the 75 - 95 higher temperatures may be partly due to effectiveness of anti-pollution policies, and you may realise that a consensus on higher temperatures may be based on sand rather than anything else.

As Andy discussed, BEST also demonstrated that rural temperature stations show essentially the same, and in fact even a slightly larger warming trend as urban and more poorly - sited stations (Figure 2).

What flavour of Urban heat warm trend do we want?

``... this robust old station, despite the urban effects, shows that there's been no statistically significant warming in Prague since 1800 (and at most 0.5 °C or so in 200 years, and I haven't subtracted any corrections for the intensification of Prague's urban heat island which may be as much as 0.6 °C per century and which would probably revert the 200 - year trend to a significant cooling!)

«We evaluate to what extent the temperature rise in the past 100 years was a trend or a natural fluctuation and analyze 2249 worldwide monthly temperature records from GISS (NASA) with the 100 - year period covering 1906 - 2005 and the two 50 - year periods from 1906 to 1955 and 1956 to 2005... The data document a strong urban heat island eff ect (UHI) and a warming with increasing station elevation... About a quarter of all the records for the 100 - year period show a fall in temperatures... that the observed temperature records are a combination of long - term correlated records with an additional trend, which is caused for instance by anthropogenic CO2, the UHI or other forcings... As a result, the probabilities that the observed temperature series are natural have values roughly between 40 % and 90 %, depending on the stations characteristics and the periods considered.»

Early on in my following of the global warming issue I became aware of the Surface Stations Survey, which led me to be very skeptical of the validity of the most recent temperature data trends, as I have never seen any convincing explanation as to how data from the many urban heat island and «corrupted» temperature monitoring sites are properly corrected.

The top panel shows the «global warming» trends of several of the global temperature estimates, and the bottom panel shows the global increase in urban population.

«Controversy has persisted over the influence of urban warming on reported large - scale surface - air temperature trends.

Lastly Parker does not seem to speculate on the fairly consistent higher trend of temperature increase he found on windy days compared to calm days, except to say it is the opposite of an urban warming signal and earlier in his paper to speculate that the windy days might not be as impacted by bad temperature sensing apparatus and siting.

«The reality of urban warming on local and small regional scales is not questioed by this work; it is the impact of urban warming on estimates of global and large regional trends that is shown to be small.»

Although urban heat islands are undeniable, many CO2 advocates argue that growing urbanization has not contributed to recent climate trends because both urban and rural communities have experienced similar warming trends.

For example, Fall et al. (2011) concluded that for all temperature stations classifications with regards to the influence of urban influences, the long - term average global warming trend is the same.

To summarize your and Steve's argument — the fact that the good and rural stations show almost no warming trend whereas the badly placed and urban ones show huge warming is not a consequence, as one might think, of the latter being affected by, you know, UHI, but, au contraire, of the former not being «properly adjusted».

A paper by Ross McKitrick, an economics professor at the University of Guelph, and Patrick Michaels, an environmental studies professor at the University of Virginia, concludes that half of the global warming trend from 1980 to 2002 is caused by Urban Heat Island.

Another paper in Climate Change in 2007 stated: Studies that have looked at hemispheric and global scales conclude that any urban - related trend is an order of magnitude smaller than decadal and longer time - scale trends evident in the series (e.g., Jones et al., 1990; Peterson et al., 1999)... Thus, the global land warming trend discussed is very unlikely to be influenced significantly by increasing urbanization (Parker, 2006).

2) Some stations must be biased warm by urban heat islands, but their influence on the global trend can't be detected with any of the techniques available for separating urban and non-urban stations.

When I said «There are also significant positive minimum temperature biases from urban heat islands that add a trend bias up to 0.2 C nationwide to raw readings», I should have said «There are also significant positive minimum temperature biases from urban heat islands, with urban stations warming up to 0.2 C faster than rural stations».

With how many people have complained about the effects of UHI, why would anyone think it means anything that a single, urban station shows a warming trend not present in the trend of its area?

Then over a decade or so, that spot goes urban and there is a huge warming trend, then once it is urban the trend settles back down and is what it is (just warmer than rural).

Combining the OAS temperatures and OAA temperatures and using the century - scale trends for each identified in the paper -LRB--0.03 K / century and +0.78 K / century, respectively), it may be concluded that instrumental temperature stations located in non-urban areas and not subjected to artificial urban heating bias produce an overall warming trend of just 0.375 K / century (0.038 K / decade) during 1900 - 2010.

Re: HaroldW (Nov 8 04:31), The newer Jones et al paper comments on this difference: «An urban - related warming trend of 0.1 C / decade is almost an order of magnitude larger than that given by Jones et al. [1990] and Li et al. [2004b].

Heat Island Effect Neglible In Overall Warming, And Skewing Climate Models The study also examined the urban heat island effect — something which climate skeptics cite as invalidating evidence of warming — and found that it had a «nearly negligible» effect on the overall warmingWarming, And Skewing Climate Models The study also examined the urban heat island effect — something which climate skeptics cite as invalidating evidence of warming — and found that it had a «nearly negligible» effect on the overall warmingwarming — and found that it had a «nearly negligible» effect on the overall warmingwarming trend.

You are also ignoring that rural stations show the same trend as urban — and that the greatest warming is observed in the far north — where there are no major urban areas.

This result could partly be attributed to the omission from the gridded data set of a small number of sites (< 1 %) with clear urban - related warming trends.

The warming trend is the same in rural and urban areas, measured by thermometers and satellites, and by natural thermometers.

In a worldwide set of about 270 stations, Parker (2004, 2006) noted that warming trends in night minimum temperatures over the period 1950 to 2000 were not enhanced on calm nights, which would be the time most likely to be affected by urban warming.

One of the improvements — introduced in 1998 — was the implementation of a method to address the problem of urban warming: The urban and peri-urban (i.e., other than rural) stations are adjusted so that their long - term trend matches that of the mean of neighboring rural stations.

But other than that, badly sited stations do warm faster (during a warming trend), as well as urban and airport stations (well sited or not).]