Catastrophic Climate Change: We Caused It; We're Going to Have to Fix It.
Reducing Waste Heat
While many focus on the greenhouse effect retaining more of the heat at the planet surface and
atmosphere, we seem to pay little attention to the amount of heating we are creating by our
activities. In particular, I am thinking of the waste heat we now produce from these sources:
- Forest Fires
- Waste heat from internal combustion engines which drive most of our transportation
- Waste heat from coal-fired electricity generation
- Waste heat which escapes houses and buildings due to poor insulation and weather sealing
- Waste heat from nuclear-powered electricity generation
- Decay heat from spent nuclear fuel in storage
- Heating from sunlight striking dark surfaces which could be more reflective
- Heating via glass surfaces which is not required (e.g. car windshields on hot summer days)
Now, contemplate this particular vicious circle. As global average temperatures rise, this will
lead to higher temperatures even in the tropics and equatorial regions. As more people are moving
to cities from rural areas in developing nations, the heat island effect of those cities will
become more pronounced. As some of these people become slightly more affluent, they will likely
purchase air conditioners to make their homes more comfortable when it is very hot.
However, in general, their houses are not built with a lot of insulation, so the cooler air will
quickly be lost to the environment. The air conditioning units are not 100% efficient, so the overall
temperature around them will increase when they are used, meaning more use of the air conditioning
units. The air conditioners run on electricity. In many developing countries, that electricity is
produced by burning coal or natural gas, which creates a lot of waste heat and greenhouse gas
emissions making the area and the planet warmer. Even if nuclear power is used to generate the
electricity, this still leads to massive amounts of waste heat, which makes the area warmer.
Which increases the demand for air conditioning.
Reducing waste heat reduces the demand for air conditioning, especially in cities. Reflective
shading (window awnings, reflective 'sails' shading roofs, PV panels placed to produce shade as
well as electricity can all help. In areas where existing buildings have minimal insulation,
'cooling rooms' should be built which are well insulated, use high-efficiency cooling units, and exhaust
their heat at the tops of buildings to reduce the impact of the heated air on residents. Cooling
chairs and vests can also be used where people understand the objective is to cool people, not spaces.