Sentences with phrase «urbanization bias»

On the basis of this claim, none of the groups calculating global temperature estimates (except for NASA Goddard Institute for Space Studies) explicitly correct for urbanization bias.

The homogenization adjustments developed by the National Climatic Data Center to reduce the extent of non-climatic biases in the networks were found to be inadequate, inappropriate and problematic for urbanization bias.

However, urbanization bias is still a significant problem, which seems to have introduced an artificial warming trend into current estimates of U.S. temperature trends.

Several studies have claimed that the warming bias introduced to global temperature estimates by urbanization bias is negligible.

The extent to which two widely - used monthly temperature datasets are affected by urbanization bias was considered.

Also, you might not think urbanization bias would be a major problem in the Arctic, since most of the big cities are at lower latitudes.

See our «Urbanization bias I» paper for more discussion.

Taken from our Urbanization bias III paper.

See our «Urbanization bias I. Is it a negligible problem for global temperature estimates?»

They questioned the reliability of the National Climatic Data Center's homogenization adjustments, and suggested that a combination of poor station exposure, urbanization bias and unreliable homogenization adjustments had led to a spurious doubling of U.S. mean temperature trends over the period 1979 - 2008.

But, when a colleague of his, Jim Goodridge, described the urbanization bias problem to him, Watts started to become sceptical about the reliability of the current «global warming estimates».

As a result, many of the records used for estimating global temperature estimates are affected by urbanization bias.

He agrees that there was some global warming over the 20th century, although he suspects much of the reported global warming is due to urbanization bias.

Rather than accurately describing the long and on - going debate which genuinely existed over the urbanization bias problem, the chapter authors ignored or dismissed the papers they personally disagreed with and presented the papers they agreed with (and in some cases had co-authored!)

However, the relevant chapter authors summarily dismissed this debate and claimed that urbanization bias was negligible.

There was plenty of very favourable discussion of the papers which claimed that urbanization bias was negligible.

See our Urbanization bias essay for a summary of why this happens.

So, the relative warmth of the recent warm period should probably be reduced somewhat, to account for urbanization bias.

In our Urbanization bias III paper, we show that their adjustments are seriously inappropriate for dealing with urbanization bias, and actually end up spreading the urbanization bias into the rural station records!

Clearly, the chapter authors had very strong views on the urbanization bias debate.

Also, Dr. Kevin Trenberth had written a comment (Trenberth, 2004 — abstract; Google Scholar access) criticising the Kalnay & Cai, 2003 study (Abstract; Google Scholar access) which suggested that nearly half of the apparent warming trends in the U.S. were probably due to urbanization bias (or land use changes).

But, there was almost no discussion of the studies which suggested that urbanization bias was substantial.

As an example of how one - sided the chapter authors could be in their reviews, let us consider the discussion of urbanization bias, since this is a topic which we have written a series of three papers on (summary here).

However, in our «Urbanization bias» papers (Summary here), we show that urbanization in the U.S. has also introduced a significant warming trend bias into the U.S. temperature estimates.

Top panel shows the mean temperature trend difference between the urban stations and the rural stations in the U.S. Historical Climatology Network for the Fully adjusted release (taken from our Urbanization bias III paper).

David Parker and Prof. Phil Jones were coincidentally co-authors of five of the papers that claimed urbanization bias was negligible — Wigley & Jones, 1988 (Abstract); Jones et al., 1990 (Abstract; Google Scholar access); Easterling et al., 1997 (Abstract; Google Scholar access); Parker, 2004 (Abstract; Google Scholar access); and Parker, 2006 (Open access).

Urbanization bias is also a problem for the Unadjusted dataset — in fact it is even more pronounced than in the Partially adjusted dataset.

In effect, they created a «consensus» on urbanization bias which coincided with their own views.

According to NASA's computer program, the more negative the slope is, the more urbanization bias there is.

In other words, urbanization bias is even a problem in the Arctic.

Estimate of the average urbanization bias in the urban U.S. stations (top) compared to the total urban population in the U.S. Click on image to enlarge.

Unfortunately, many of the weather station records used for these estimates are affected by urbanization bias.

In addition, because urbanization bias continues to increase from year to year, this means that they have to keep on increasing their adjustments every year, meaning that «history is continuously being rewritten».

As we discussed in Section 2, we know that the Buenos Aires record is affected by urbanization bias.

Interested readers are welcome to read our three papers for a detailed assessment of the urbanization bias problem.

A weather station which we know is highly affected by urbanization bias, the Buenos Aires station we discussed in Section 2

AndThenTheresPhysics, I think John is referring to the claim in Jones et al., 1990 that the contribution of urbanization bias to global temperature trends is less than 0.05 °C / century.

This suggests that the «warming» in the Buenos Aires record during those years was just urbanization bias.

In this essay, we summarise the main points of our three «Urbanization bias» papers, which we have submitted for peer review at the Open Peer Review Journal.It has been known since at least the 19th century that urban areas are warmer than rural areas.

The various attempts that have so far been made to deal with the urbanization bias problem have been woefully inadequate.

On the basis of this remarkable claim, none of the groups except for the Goddard Institute of Space Studies currently attempt to correct their estimates for urbanization bias, as can be seen from Table 1.

The «urbanization bias» corrections their computer program calculates are unrealistic, unreliable, inadequate, and often just plain inappropriate!

Have you read our papers on Urbanization bias yet?

This bias is called «urbanization bias».

Well, if you look at the bottom panels of Figure 32, you can see that most of the neighbours the program used are urban stations, i.e., the neighbours are also affected by urbanization bias.

Even small isolated towns in the Arctic, such as Barrow, Alaska (USA) have been affected by urbanization bias.

If you want to seriously study the effects of urbanization bias, you can't just use a simplistic «either / or» approach to distinguishing stations, e.g., see Stewart & Oke, 2012 (Open access).

Changes in microclimate can also lead to non-climatic biases, but these are distinct from the urbanization bias problem.

Having said that, we saw in Section 2 (Figures 12 & 13) that the highly urbanized stations are significantly affected by urbanization bias, with the bias introducing a warming bias of roughly 0.7 °C / century.

They decided to develop a computer program which would automatically search through the weather station records and apply adjustments to remove any urbanization bias.