Cities, towns most vulnerable to climate change's wrath
Published:Saturday | September 30, 2023 | 12:05 AMAsha Wilks/Gleaner Writer -
ACCORDING TO experts, urban regions are more vulnerable to the detrimental effects of climate change than rural ones. The experts also believe that more action is required to address the global crisis, which puts small-island states like Jamaica at greater risk from these effects.
Dr Jenna Blackwood, landscape architect and environmental consultant, emphasised the importance of incorporating nature into developments to promote cooler atmospheric temperatures.
She was presenting at the first session of the Science for Today public lecture series recently hosted by The University of the West Indies’ Faculty of Science and Technology. Titled ‘Too Hot to Handle’, the lecture examined how climate change continues to affect the environment and various industries.
Speaking on her selected topic, ‘Climate change and landscapes: Using nature to beat the heat', Blackwood said that people were mostly responsible for the various changes to the landscape that resulted in warmer temperatures in urban areas.
She emphasised that various landscapes, such as the coastal, agricultural, mountain and others have undergone changes, many of which had negative effects.
Looking at the phenomenon known as the urban heat island effect, Blackwood showed a chart which depicted rural areas experiencing temperatures below 30 degrees Celsius in late afternoon.
In contrast to this, the chart showed urban residences, commercial spaces, suburban residences and downtown regions with temperatures well over 30 degrees Celsius.
The urban heat island effect occurs when cities replace natural land cover with dense clusters of pavement, buildings and other surfaces that absorb and retain heat.
“We also tend to remove plant materials, changing the ecology of the space. We're not getting as much moisture in our soils, we have cars that are putting out greenhouse gases and interestingly, air conditioners ... [when cooling] inside, [they] are actually putting out, on the outside, heat as well and contributing to the heat that we’re experiencing,” she explained.
Other factors include the increased use of materials like asphalt, concrete, and metal that raise atmospheric temperatures; the paving of more city streets and driveways, which prevents rainwater and moisture from being absorbed to cool the atmosphere; and the erection of taller structures, which, despite casting shadows in some places, acts as a barrier to winds that would otherwise cool the atmosphere.
Blackwood also discussed how the nation’s natural water cycle is being disrupted by urbanisation, and expressed the need for more solutions to be developed to replace the loss.
One of the concerns she asked herself was, “If we don't give water back to the environment, how do we expect to get any back?”
“So, if we are not allowing the system to function as it used to, then it becomes more difficult for us to get [it] back in the form of rain, in the form of the rivers and streams, as they end up drying,” she continued.
Blackwood therefore called for more to be done in the construction industry to encourage ecosystem-based adaptation efforts that are crucial to protect landscapes.
This would entail strategically incorporating nature and the use of green spaces into the construction of both residential and commercial complexes, as well as the building of structures that encourage convection and air movement, to minimise the use of air conditioners and other energy-consuming appliances; the implementation of green roofs and walls to provide insulation to buildings, preventing the sun from touching its surface; and adding moisture to areas by using bird baths or creating man-made ponds to help cool the atmosphere, Blackwood said.
“I don’t think that we can continue to do things in the way we have been doing it and expect to make things any better,” she said.
... People being pushed beyond capacity to adapt
Jacqueline Spence-Hemmings, head of the Meteorological (MET) Service's climate branch, who was a part of the panel, emphasised that human-induced climate change has had significant effects on both nature and people. She said this in reference to the most recent findings of the Inter-governmental Panel on Climate Change (IPCC) working group two (WGII) assessments. Some of these effects have already become irreversible, and economic damage estimates are higher than previously anticipated.
She pointed out that because of increased weather and climate extremes, people and ecosystems are being pushed beyond their capacity for adaptation, with small islands like Jamaica being among the most at risk.
“Almost half of the world’s population is living in contexts that are highly vulnerable to climate change, increasing weather extremes, including tropical cyclones ... [that are] driving displacement of people around the world,” she said, raising the concern of what this means for small islands and their inhabitants.
Spence-Hemmings explained that Jamaica’s rainfall pattern consists of two peaks: the primary peak period, which falls between the months of August and November, which coincides with the Atlantic hurricane season, when Jamaica typically experiences higher rainfall; and the secondary peak, which falls between the months of April and June.
She adds that there has been a worrying trend of more months in 2021 being below-average in the nation's parish count of below-normal, and normal to above-normal rainfall pattern.
“Looking at 2022, [it’s] not much better. We did get some rainfall in April, above-normal, but then it quickly disappeared for May. June again was considered below-normal,” she said.
Spence-Hemmings said that this was a result of the pattern of extended drought periods being experienced.
She added that the highest temperatures ever recorded in Hampden, Trelawny, in 2020, soared beyond 30 degrees Celsius.
Despite a downward trend in 2021 and 2022, she pointed out that the figures are climbing again this year, where a temperature record of 37 degrees Celsius was set in September.
“These are not normal temperatures, people, just in case you are wondering,” she said.
Looking at temperatures in another area of the island, the Norman Manley International Airport in Kingston, Spence-Hemmings noted similar trends of higher temperatures being experienced.
“On average, we would say that between 31.2 and about 33 [degrees Celsius] is normally average. For April, it gets a little warmer ... and it should start to go down in about August when you get rainfall. [But] now, for this year, what we are seeing is that, instead of going down, some of the temperatures actually went up,” she explained.
She added that the same was for the Sangster International Airport in Montego Bay, St James.
“You see a more clearer pattern of increase in temperature. You can actually see the uprise in temperature for each month ... and this is April through August,” she said of the period 1990 to 2023, with 25 days in August 2023 experiencing temperatures at 34 degrees Celsius.
She expressed the view that the effects of climate change will have an influence on economies, the environment, the health sector, and the agricultural sector, endangering lives and livelihoods.
“Some years ago, there was a study that came out in 2013 by a scientist, Mora. He’s in Hawaii and he said at that time that Kingston was going to be the first city in the western hemisphere and the second in the world that would experience climate departure by 2023,” said Blackwood.
She pondered about how true these projections were, given that temperatures experienced in recent months were abnormal and unprecedented.