Human greenhouse gas emissions by sector, in the year 2010. AFOLU“ stands for „agriculture, forestry, and other land use“. Graph of net crop climate Change. Have scientists failed to give sufficient warnings? PDF worldwide and in selected tropical countries. Raw data from the United Nations.
Författare: Marcel Riguez.
Studienarbeit aus dem Jahr 2016 im Fachbereich Politik – Internationale Politik – Klima- und Umweltpolitik, Note: 2,7, Bayerische Julius-Maximilians-Universität Würzburg (Englische Philosophie), Veranstaltung: Climate Narratives, Sprache: Deutsch, Abstract: This term paper discusses different reasons, why scientists may have failed to give sufficient warnings about climate change and why mankind does not want to listen.
Most scientists are well-meaning and often altruistic. They are looking to find out what is the "truth" in order to explain and help society and nature. If such a person sends urgent warnings because of their research findings, it is fascinating how the public reacts. One evocative reaction comes from Naomi Oreskes and Erik M. Conway’s Book The Collapse of Western Civilization. The narrator is a historian in the future, blaming our society for ignoring the obvious.
Climate change and agriculture are interrelated processes, both of which take place on a global scale. Climate change is already affecting agriculture, with effects unevenly distributed across the world. Agriculture contributes to climate change both by anthropogenic emissions of greenhouse gases and by the conversion of non-agricultural land such as forests into agricultural land. A range of policies can reduce the risk of negative climate change impacts on agriculture and greenhouse gas emissions from the agriculture sector. For each plant variety, there is an optimal temperature for vegetative growth, with growth dropping off as temperatures increase or decrease. Similarly, there is a range of temperatures at which a plant will produce seed. Outside of this range, the plant will not reproduce.
On the other hand, agricultural trade has grown in recent years, and now provides significant amounts of food, on a national level to major importing countries, as well as comfortable income to exporting ones. Climate change induced by increasing greenhouse gases is likely to affect crops differently from region to region. More favourable effects on yield tend to depend to a large extent on realization of the potentially beneficial effects of carbon dioxide on crop growth and increase of efficiency in water use. They are large uncertainties to uncover, particularly because there is lack of information on many specific local regions, and include the uncertainties on magnitude of climate change, the effects of technological changes on productivity, global food demands, and the numerous possibilities of adaptation. Most agronomists believe that agricultural production will be mostly affected by the severity and pace of climate change, not so much by gradual trends in climate.
If change is gradual, there may be enough time for biota adjustment. But much remains unknown about exactly how climate change may affect farming and food security, in part because the role of farmer behaviour is poorly captured by crop-climate models. Global warming could lead to an increase in pest insect populations, harming yields of staple crops like wheat, soybeans, and corn. The University of Illinois conducted studies to measure the effect of warmer temperatures on soybean plant growth and Japanese beetle populations. The increased CO2 levels deactivated three genes within the soybean plant that normally create chemical defenses against pest insects. One of these defenses is a protein that blocks digestion of the soy leaves in insects. Since this gene was deactivated, the beetles were able to digest a much higher amount of plant matter than the beetles in the control field.
This led to the observed longer lifespans and higher egg-laying rates in the experimental field. There are a few proposed solutions to the issue of expanding pest populations. One proposed solution is to increase the number of pesticides used on future crops. This has the benefit of being relatively cost effective and simple, but may be ineffective. Although research is limited, research has shown that climate change may alter the developmental stages of pathogens that can affect crops. The biggest consequence of climate change on the dispersal of pathogens is that the geographical distribution of hosts and pathogens could shift, which would result in more crop losses.
Effects of regional climate change on agriculture have been limited. Changes in crop phenology provide important evidence of the response to recent regional climate change. Droughts have been occurring more frequently because of global warming and they are expected to become more frequent and intense in Africa, southern Europe, the Middle East, most of the Americas, Australia, and Southeast Asia. Their impacts are aggravated because of increased water demand, population growth, urban expansion, and environmental protection efforts in many areas. As of the decade starting in 2010, many hot countries have thriving agricultural sectors. Jalgaon district, India, has an average temperature which ranges from 20.
It produces bananas at a rate that would make it the world’s seventh-largest banana producer if it were a country. During the period 1990-2012, Nigeria had an average temperature which ranged from a low of 24. C in January to a high of 30. In 2013, according to the FAO, Brazil and India were by far the world’s leading producers of sugarcane, with a combined production of over 1 billion tonnes, or over half of worldwide production. In the summer of 2018, heat waves probably linked to climate change cause much lower than average yield in many parts of the world, especially in Europe. Depending on conditions during August, more crop failures could rise global food prices. Overall food shortages are not expected this year.
As part of the IPCC’s Fourth Assessment Report, Schneider et al. Most of the studies on global agriculture assessed by Schneider et al. Studies had also not considered the development of specific practices or technologies to aid adaptation to climate change. Projected changes in crop yields at different latitudes with global warming. This graph is based on several studies. Projected changes in yields of selected crops with global warming. Their central estimates of changes in crop yields are shown above.
Actual changes in yields may be above or below these central estimates. The IPCC Fourth Assessment Report also describes the impact of climate change on food security. The same set of greenhouse gas and socio-economic scenarios were also used in projections that included the effects of climate change. Projections also suggested regional changes in the global distribution of hunger. By 2080, sub-Saharan Africa may overtake Asia as the world’s most food-insecure region. This is mainly due to projected social and economic changes, rather than climate change.