Global temperature has always varied...

Maanantai 23.9.2024 klo 18.43 - Mikko Nikinmaa

Climate change deniers (I use that term for people who maintain that human actions are not affecting climate) invariably state that global surface temperatures of the earth have varied markedly throughout the geological history. This is, indeed, true. A thorough study about temperature variations on earth was recently published by Judd et al. in Science (Science 385 eadk 3705; Sept 20, 2024). Indeed, the study clearly shows that the global surface temperature has varied markedly during the past 500 000 000 years. Furthermore, the present temperature is at the lower end of the temperature variations. So, the climate change deniers can be happy, it is more likely that global temperatures increase than anything else. Or can they?

I would say not. One can now place the extinction waves in the temperature diagram. Before the present, there has been five massive extinction events in the earth’s history. Four out of five have occurred when the surface temperature has increased markedly and only one can be associated with temperature decrease. Why is a temperature increase more fatal to life than temperature decrease? One explanation is seen already when temperature tolerance of animals is estimated. They can survive long periods of time at temperatures much below optimal, but succumb rapidly at temperatures only a few degrees above optimal. Indeed, high activity cannot be achieved at high temperatures as the heat produced by the activity cannot be dissipated, but causes structural damage to proteins rendering them inactive. Thus, it is likely that if we now are faced with a temperature increase, another extinction event is likely to occur.

The study by Judd et al. clearly shows that temperature variations are much more tightly associated with carbon dioxide level than earlier estimated: increased carbon dioxide necessarily causes temperature increase and decreased carbon dioxide temperature decrease. This being the case, it is clear that the human-induced increase in carbon dioxide level will cause temperature increase. Since, further, the increase in carbon dioxide level has been thousands of times faster than the earlier changes, it is likely that the effects on extinctions are more pronounced than in earlier geological times.

Thus, although Judd et al. study clearly shows the global surface temperature has been higher than presently many times in geological history without human influence, the changes of the past  indicate the need for preventing carbon dioxide increase.

Kommentoi kirjoitusta. Avainsanat: climate change, carbon dioxide, extinctions

Sharks are terrible - but also endangered

Keskiviikko 8.9.2021 klo 14.35 - Mikko Nikinmaa

The IUCN red list was again published. Although it is not able to give a full account of what the status of animal and plant species is, it gives an estimate of how nearly 140 000 species are doing in today’s world. There are some species, which are doing better today than in earlier year, but others, which are doing worse. Here I focus on fish, because they are of special interest to me. The red list information in full can be found at //www.iucnredlist.org/

The tuna species have long been among the endangered ones. However, it now seems that their stocks are recovering. This shows that if enough attention is placed on the status of a species, recovery is possible. The recovery of tuna populations is certainly due to the following: 1. The DNA of tuna catches has long been checked, so that catches including meat of the most vulnerable species could not be sold. This has directed tuna fishing towards the species not at risk. 2. The aquaculture of tuna has begun to be successful. This being the case, the need to fish natural tuna populations has decreased.

However, whereas tunas have started to recover, the same cannot be said of sharks and rays. Around forty percent of these cartilaginous fish are endangered. Virtually always, when sharks are in the news, they have killed or maimed a swimmer. Also, movies like the Jaws portray a negative picture of sharks. Consequently, they are considered to be evil, whereby very few people are against their disappearance. Yet, they are important components of healthy marine ecosystems, and the extinction of sharks leads to their deterioration. One of the main reasons for shark fishing is their use in shark fin soup. It has been considered a delicacy in Chinese cooking. In the quest for shark fins, only the fins were saved of the catch, and the rest of the shark thrown back to the water. Recently, there has been strong campaign against the use of shark fins, but at least as yet it has not helped the diminished stocks. The reason for this may be twofold: first, sharks reach sexual maturity late (often they are more than 10 years old), and reproduction is viviparous in many species with only a couple of pups born.

So, we should be worried about the disappearance of sharks. They are needed for keeping marine ecosystems healthy. The other animal group with a large proportion of species endangered is amphibians. They are suffering from the destruction of wetlands. Wetland destruction should be discontinued even if the purpose is not protecting amphibians, as it makes coastlands increasingly vulnerable to storms and flooding.

Kommentoi kirjoitusta. Avainsanat: biodiversity loss, extinctions, marine ecosystems, wetlands, amphibians, tuna

The Earth Day - 49th time

Maanantai 22.4.2019 klo 12.54 - Mikko Nikinmaa

It is again Earth Day, and compared to last year the state of the earth has not improved. The predictions are gloomier and gloomier. However, there is much to be pleased about, despite the gloomy predictions. The state of environment, especially climate change and plastic pollution have become front page news. Although many people are of the opinion that one should not scare people by giving them too negative news, it appears that IMG_20170727_0037_NEW.jpgnothing is accomplished unless a catastroph is imminent.

As a flagship for Earth day one could take Our Planet, now available in Netflix. David Attenborough (born 1926) is still avtive, and his documentary, showing different aspects of the earth clearly indicates that the beauty and diversity of world is far too great to be given up. This is so especially, as we have the means to combat climate change and other environmental problems. With regards to plastic pollution, it doesn't even require significant funds, just a change of attitude all over the world. What is worrying that plastic collected in Industrialized Western Countries has recently been found disposed in the environment in Malaysia. It is not the way that collected plastic should be found. A likely reason for such finding is that China has stopped importing plastic waste. However, the stop of import should not result in throwing the problem elsewere, it should result in treating the material where it is used. In the case of climate change, we need to be willing to set aside funds. However, most people are certainly willing to give up some of the money we have taken as loan from future generations. The problem is people, whose attitudes are from the past, when there were only 2 billion people in the world, when Europeans dreamed of big Amerrican cars and petrol was cheap and coal mines an important work place.  Such people should see that thing are different now, and stop resisting actions that are needed to keep world beautiful as in Our World.

Kommentoi kirjoitusta. Avainsanat: climate change, extinctions, environmental conservation

Climate change, biodiversity loss - reincarnations of population bomb

Perjantai 2.11.2018 klo 12.46 - Mikko Nikinmaa

Very recently several important contributions on environmental questions have been published. First, the IPCC report on Climate Change, and, second, the WWF Living Planet 2018 report  (WWF. 2018. Living Planet Report 2018. Aiming Higher. Grooten, M. and Almond, R.E.A.(Eds). WWF, Gland, Switzerland.). In addition, an article in Nature (Resplandy et al. 2018   Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition, Nature 563, 105-108) indicates that more heat has been absorbed by the oceans than conservative estimates suggest, i.e. that climate change may be worse than previously thought

Surprisingly, the reports do not give virtually any attention to the size of human population, although looking at the above two pivtures, a striking similarity in the population increase and athospheric carbon dioxide level graphs can be seen. In the future, it can unfortunately be estimated that if climate actions are not effective, carbon dioxide production increases much more than population growth, since population growth occurs in areas, where carbon dioxide production per person has increased markedly during recent past. Also, the major reasons for the huge (60 %) biodiversity loss are habitat loss and exploitation, both the result of the need of increasing population to get food and other commodities.

It is shocking that economic circles and politicians throughout the world forget that all economic activity ultimately depends on healthy environment. As a result, growth is not possible indefinitely, and economic theories should center not around growth but around sustainability. And one of the major aims of future global planning should be to limit world population. However, as long as the growth-based ideology predominates, population growth is needed. Naturally, actions to corb population growth should be such that nobody is offended. I have toyed with the idea that foreign aid would be given to individuals, not the (mostly corrupt) governments. The direct funding would depend on the size of the family, increasing with a decrease in the number of children. Another significant action would be the schooling of women: this would significantly decrease the population growth, and would also foster equality - certainly opposed by many in male-dominated societies.

Many innovative solutions to decrease the exploitation of wild animals and habitat distruction have been already advanced. Also, there are a plenty of possibilities to decrease the energy needed for transporting goods and new ways of energy production. However, in my opinion, a success in combatting both climate change and biodiversity loss requires that we are succesful in limiting population growth. If we cannot do that, there is bound to be a collapse resembling one that is always seen with animal populations, which have become too dense.

Kommentoi kirjoitusta. Avainsanat: land use, extinctions, energy consumption, carbon dioxide

State of the world - what has happened in 25 years

Lauantai 18.11.2017 klo 12.40 - Mikko Nikinmaa

Twenty five years ago the Union of Concerned Scientists wrote "World Scientists' Warning to Humanity" (with the major authors and 1700 scientists' signatures) where they were concerned about population growth, freshwater availability, climate change, extinctions etc. Now, scientists have looked at what has happened in the past 25 years, and concluded that "World Scientists' Warning to Humanity: Second Notice" was in order. This article was published on November 13 in Bioscience with William J. Ripple as the first author (in addition to the major authors the article had 15,364 scientist signatories from 184 countries). Apart from the ozone hole, which is now starting to shrink, all the environmental problems recognized in 1992 have become worse, and are still continuing to be more detrimental. For example, the amount of carbon dioxide emissions has increased in the last year after it had stabilized or even slightly decreased in the previous two years. In the past 25 years, the availability of fresh water has decreased by 25 %, mean global temperature increased by 0.5 degrees C, carbon dioxide emissions have almost doubled, the dead zones in marine areas increased by almost a third, forests decreased by about 5 % and vertebrate species number decreased by about 30 %. Although human population growth has stopped in the developed countries, the same thing has not happened in Africa and most Asian countries, whereby the total world population has increased by almost 40 % with no sign of increase rate to be slowing down. The number of extinctions in vertebrates is probably much smaller than that of invertebrates - for example insect biomass in certain protected areas in Germany has decreased by 75 %. A significant problem is also that despite increased catching effort, the marine fish catches have decreased by about 20 % from the best years. One final note of the gloomy statistics, we consider almost always only deforestration as causing a decrease in carbon dioxide removal. However, because of the prevalence of sea area, almost half of global photosynthetic activity takes place in marine algae. Marine pollution has decreased algal photosynthesis by approximately 10 % in the past 25 years.                                

Although most of the indices show radical worsening in the state of global environment, the situation with ozone hole indicates that if mankind heeds the warnings, we are able to make the changes required to keep the environment in satisfactory state. The stratospheric ozone layer above Antarctica is now strongest since 1988. If similar united actions were done for the other questions pinpointed by the authors of the Bioscience article, they could also be solved in reasonable fashion. Changes of diet, schooling, improvement of women's situation, discontinuation of fossil fuel use could all be done if we so decided.

Kommentoi kirjoitusta. Avainsanat: deforestration, population growth, fisheries, climate change, extinctions

Declines in bird and butterfly populations

Keskiviikko 12.4.2017 klo 10.07 - Mikko Nikinmaa

In British Isles bird and butterfly populations have been carefully monitored probably for the longest time in the world. Thus, the observations made there are probably significant for the rest of the world. Recently the estimations of bird and butterfly populations from Britain have come out and they are frightening. About a quarter of bird species have been placed in more vulnerable categories in the red list than after previous estimations. The species in decline are surprisingly often the non-conspicuous ones, whereas notable species with population increase include for example golden eagle. More than half of British butterfly populations have declined since 1970's. The single most important reason of declines of populations in both animal groups has been suggested to be climate change which also has resulted in a change in land use. 

Kommentoi kirjoitusta. Avainsanat: red list, climate change, extinctions