From Concrete to Wood in Building: Combatting Climate Change

Keskiviikko 18.12.2019 klo 14:53 - Mikko Nikinmaa

Another indication of the climate change is the observation that Australia experienced the hottest day ever. Despite this and a multitude of other signs, the backward-looking politicians like the Australian prime minister thwart any actions to combat climate change. President Trump lists as one of his major achievements “cancellation of the unfair and costly Paris Climate Agreement”.

The discussion about climate change has concentrated on coal and oil use in energy production and on eating meat. Also flying and rain forests have attracted much media attention. It is seldom mentioned that the size of the human populIMG_20170809_0038.jpgation is a problem, and actually makes the populistic solution of going back to the past impossible. In the past that the backward-looking leaders want to return to, there were two-three billion people, now we are about eight billion. With two-three billion people, limits to growth had not been reached, now they have. The importance of unicellular algae of the ocean in generating the oxygen balance by photosynthesis is often not acknowledged. Yet, almost half of the oxygen-generating photosynthesis is carried out by these small algae. Finally, one of the important carbon dioxide sources is concrete building – it accounts close to ten percent of the present carbon dioxide emissions.

Thus, one should stop building using concrete and steel. Most of the carbon dioxide emissions are due to cement production, an indispensable component of concrete. Making brick or stone houses would already be much better than concrete. However, the pest alternative would be wooden houses. Technologies are already available, which enable building multi-store houses. Further, the probability of burning of wooden houses is much reduced from 19th century, when whole cities could burn. In a wooden house the carbon would be stored for its entire life length, up to several hundred years. Thus, if all new buildings were wood-based, the carbon footprint of building sector would decrease for 10 % of world total to 0. This would be a huge win in combatting climate change, and could be reached with the presently available techniques. In view of this, one must ask: why is it not done?

Kommentoi kirjoitusta. Avainsanat: carbon footprint, population growth, Paris Climate Agreement, temperature

Climate change - why seas matter

Keskiviikko 25.7.2018 klo 16:37 - Mikko Nikinmaa

Compared to the terrestrial environment the seas contain fifty times more carbon dioxide. Further, about half of all photosynthetic carbon dioxide removal is done by oceanic organisms, mainly phytoplankton, which partly remove carbon from circulation, when they sink to seabottom after dying.

An increasing temperature decreases the solubility of carbon dioxide and ocean acidification means that the equilibrium between carbon dioxide, bicarbonate and carbonate is driven towarIMG_20170727_0010_edited_101412.jpgds carbon dioxide. Further, the pollution of the seas has resulted in reduced  photosynthesis despite eutrophication in some areas.

The net result of the above is that liberation of the greenhouse gas, carbon dioxide, from the seas to the atmosphere increases simultaneously as its photosynthetic fixation decreases. Furthermore, the marine environment enters vicious circle: the higher the temperature and lower pH, the more carbon dioxide enters the atmosphere and causes further temperature increase.

The well-being of the seas thus matters - also in mitigating climate change.

Kommentoi kirjoitusta. Avainsanat: carbon dioxide, greenhouse gases, carbon footprint, ocean acidification