From JoNova

By Jo Nova

Who knew, we can solve global warming by moving suburbs, planting trees, limiting immigration?

A new study used satellite data to look at ten cities around the world to see which parts of cities are the warmest, and how that has changed in the last twenty years as they grew.

It looks like man-made global warming mainly applies to airports and industrial areas. We put most of our thermometers at airports which awkwardly turn out to be 2.5 degrees Celsius warmer than surrounding areas, and presumably warmer than they were 120 years ago when there wasn’t 3 square kilometers of concrete runway there sitting in the sun. Industrial zones were even worse, being 2.8°C hotter. Conversely leafy green areas with a lot of vegetation were nearly 4 degrees cooler than the average. So airports are at least 6 degrees warmer than forests.  Places near bodies of water were, not surprisingly, even more than 4 degrees cooler. It’s part of why people pay $5 million for a beachside mansion isn’t it?

The worst climate change in Melbourne is on Boundary Road

One of the ten cities they studied was Melbourne and there is a special mention for Boundary Road in Laverton North where daytime temperatures rose from 22.49 °C in 2001 to 30.82 ° in 2021. So that’s 8 degrees of warming in 20 years, surely the fastest rate of warming in a million years. Bring out your dead?

This 8 degree local warming trend compares to a general city-wide background warming effect over the twenty years of about 0.5°C.

Contrast that apocalypse with the western Quandong region, which is primarily agricultural.  There man-made climate change caused a cooling trend of −0.12 °C/year during the day.

Does anyone really care about the workers in the urban deserts?

The next time a smug Blob Academic panics about how 1.5 degrees of global warming will imperil pregnant women, babies, and cats and dogs, let’s ask them if they know of the deadly microclimate threat. If a small rise in temperature is that serious, all the mascots, I mean victims, face a far bigger threat from high density development and unrestrained urban population growth than from coal and gas power plants a hundred miles away.  When the experts tell us climate change causes school students marks to fall, or ruins the sleep of senior citizens, we can ask them why they think windmills and solar will cool folks better (or cheaper) than tree canopies? I mean, do they care or don’t they?

And instead of installing 4 million solar panels on rooftops in the hope of shifting ocean currents to cool the suburbs, we could have planted trees instead. And given that we chop down trees that shade the panels, the big question is whether the local heating effect of solar panels can ever be compensated for by altering Antarctic jet streams via carbon reduction. These people are witchdoctors.

The next time the electricity grid managers plot and scheme to switch off our air conditioners at peak times, we can ask them whether tree planting has a better cost-benefit ratio than demand management. Is it cheaper to grow trees or to turn off smelters and factories at 6pm?

I’m sure there’s room for a thousand PhD theses comparing microclimate management as a way to solve “climate change” and I’m also sure most of them will never be done.

If anyone really believes an extra degree is dangerous, the fastest, cheapest fix is air-conditioning with cheap electricity. But in the long run, the lifestyle answer is trees, parks, and ponds. Not “green steel,” not jet-stream manipulation, not billion-dollar grid schemes. Just shade, water, and leaves — the original solar harvesting technology.

The ten cities they compared were spread across the world: Cairo (Africa), Chongqing (Asia), Delhi (Asia), Istanbul (Europe/Asia), Melbourne (Oceania), Mexico City (North America), Moscow (Europe), Nuuk (North America), São Paulo (South America), and Tokyo (Asia).

Details from the paper below:

Airports exhibited a mean daytime land surface temperature (LST) that was 2.5 °C higher than surrounding areas, while industrial zones demonstrated an even greater temperature disparity, with an average increase of 2.81 °C. In contrast, cold spots characterized by dense vegetation showed a notable cooling effect, with LST differences reaching −3.7 °C. Similarly, proximity to water bodies contributed to temperature mitigation, as areas near significant water sources recorded lower daytime LST differences, averaging −4.09 °C.

3.2.5. Melbourne

In Melbourne, land surface temperatures (LSTs) around the city center have shown moderate increases over the past two decades. In 2001, the average daytime LST was 23.74 °C, and nighttime LST was 8.17 °C (Figure 12). By 2021, these values had risen to 24.13 °C during the day and 8.73 °C at night, reflecting a slight warming trend associated with urbanization and infrastructure development.

Hotspot regions primarily include industrial and commercial areas such as Laverton North, Melbourne Airport, Somerton, Campbellfield, Essendon, and Dandenong South. Among these, industrial facilities (recycling, logistics, and warehouses) on Boundary Road in Laverton North recorded the most dramatic rise, with daytime LST increasing from 22.49 °C in 2001 to 30.82 °C in 2021 and nighttime LST rising from 7.29 °C to 8.79 °C. This sharp increase underscores the thermal impact of industrial activities and impervious surface expansion. In contrast, forested northern regions showed minimal temperature changes, maintaining their cooling effect. In 2001, daytime and nighttime LSTs in these areas were 13.13 °C and 7.49 °C, respectively, compared to 13.17 °C and 7.87 °C in 2021.

The analysis of temperature trends in Melbourne indicates gradual warming in the city center, with a daytime LST trend of +0.030 °C/year and a nighttime trend of +0.033 °C/year. The most significant increases were observed in hotspot areas such as Dandenong South, where daytime LST rose by +0.17 °C/year and nighttime LST by +0.067 °C/year, reflecting intense industrial activities and urban development. An intriguing contrast emerges in the western Quandong region, which is primarily composed of agricultural lands. Here, a cooling trend of −0.12 °C/year during the day is observed, alongside a minimal nighttime increase of +0.007 °C/year. This suggests that the retention of vegetation and agricultural practices may be mitigating daytime heat, though slight thermal retention is evident during the night.

From 2001 to 2021, in Melbourne, urban areas showed surface temperature increases of 0.02 °C/year during the day and 0.03 °C/year at night, reflecting urban warming trends (Figure 13). Vegetation experienced a slight cooling of −0.02 °C/year during the day and a warming of 0.02 °C/year at night, while bareland cooled during the day by −0.03 °C/year and warmed at night by 0.03 °C/year. Water body surface temperatures showed no daytime trend but increased significantly at night by 0.05 °C/year, indicating nighttime oceanic warming near urban areas.

h/t Esra Taf

REFERENCE

Yiğitalp Kara ^1,2,* and Veli Yavuz ^{1 (2025)} Urban Microclimates in a Warming World: Land Surface Temperature (LST) Trends Across Ten Major Cities on Seven Continents, Urban Sci. 2025, 9(4), 115; 

https://doi.org/10.3390/urbansci9040115