Numbers are part of carbon cycle
In his Jan. 5 letter “CO2 and its effect on climate change,” the writer cites data which is open to question. In the first paragraph he says that during the period from 1996 to 2015 satellite-derived data show no increase in world temperature. In fact, NASA data show significant and accelerating temperature rise in that period (see climate.nasa.gov/vital-signs). The same site shows excellent CO2 data.
The writer then cites incomplete CO2 source data. For instance, he says oceans send 46 percent of the total CO2 into the atmosphere annually. True, but he doesn’t mention that more CO2 is absorbed by the oceans than is sent to the atmosphere. On average, the oceans release 332 gigatons to the atmosphere each year, while 338 gigatons are absorbed. So the oceans provide a reduction in surface CO2. Again, his data show soils emit 26 percent of total atmospheric CO2. Annual soil-derived CO2 sent to the atmosphere equals about 439 gigatons, but 450 gigatons are absorbed.
All the above numbers are part of the well-known carbon cycle, which has held CO2 in a reasonable range, because of exchange between oceans, land and atmosphere. However, the 29 gigatons of CO2 released annually by burning fossil fuels cannot all be accommodated by the carbon cycle and accumulates in the atmosphere and oceans, making the land warmer and the ocean more acidic.
We need to deal with that 29 gigatons of CO2 from fossil fuels.