Another week of heat. Despite the steamy air, the soil in the garden is dust, the plants stunted, unwatered lawns brown and wells going dry. It shouldn’t be a surprise. According to the National Weather Service, last December was the warmest on record. The first snowfall, which arrived on Dec. 29, was the latest on record.
2015-16 was the winter that wasn’t, with frequent T-shirt days for teens and bare ground. The summer continues to be hot and, despite brief storms, dry. This could be the new normal or, as many climate change believers say, only the start. By mid-century, according to experts at UNH, New Hampshire’s climate could be like that of Virginia or even North Carolina.
Concord should be doing more to prepare for the hot days ahead, protect the health of its citizens and avoid making the problem worse by burning ever more fossil fuel to run air conditioners.
For a century or more, tall shade trees lined city streets and still do in a southern communities.
In Concord, as in most cities, they’ve succumbed to salt, soil compaction and the need to reduce power outages. The result has been hotter streets and homes, a growing use of air conditioners, and increased line loss since heat reduces their efficiency.
To the extent it can, the city, and homeowners, should plant trees that will provide blessed shade.
Trees consume water, which, if climate models are right, is more likely to arrive in the form of potentially flood-provoking deluges than the steady rains of old. Culverts will have to be increased and drainage systems installed or upgraded. Far more road and parking surfaces should be covered with permeable pavers, akin to those in White Park, or porous asphalt. That would not only reduce runoff but increase soil absorption and recharge aquifers. Zoning changes may be in order.
Permeable pavers have a higher albedo than traditional asphalt. Albedo is the percentage of light reflected by a surface, which affects its surface temperature. Black asphalt pavement, in a test in Phoenix conducted by Lawrence Livermore National Laboratory, hit temperatures of 158 to 176 degrees.
That heat, which anyone who has crossed a mall parking lot on a scorching day has experienced, creates a heat island with higher temperatures than surrounding areas. Cities themselves are heat islands visible on satellite maps.
An increase in albedo can significantly reduce daytime temperatures, the lab study concluded. Several methods have been used to reduce the heat island effect from pavement.
They include porous pavers, asphalt with reflective additives and Portland cement. Porous pavers, which allow water to evaporate when wet, have the highest cooling effect and lowered surface temperatures by 35 to 95 degrees.
Finally, the hotter the temperature the worse the effect on health and the greater the effect on air pollution.
More hot weather will require making efforts to reach out to the elderly and poor who may not have access to air conditioning or fans.
The need to operate cooling centers will increase, as will the need for neighbor-checking-on-neighbor programs, limitations on strenuous activity, a greater focus on food safety and increased emergency readiness.
Under the highest carbon dioxide projection used by UNH forecasters, summer temperatures could eventually average 11 degrees higher than in the period 1980 to 2009. Not quite the tropics, but not what New Hampshire used to be.
Concord should be ready.