Here is a helpful essay from Dr. Reddy too. It is argued by the IPCC that models that predict future temperature scenarios are based on physical principles but at the same time accepting the fact that there are several other localized or globalized factors contributing to it. Such factors are rarely accounted for in their models. Thus, there are no clear cut physical principles concerning global warming. It is basically statistical inferences that vary with data and period. The IPCC uses the number of people accepting the predictions to validate it. In science, unless they are verified by ground realities, they are generally termed as “hypothetical”, which has no meaning in science. The IPCC is sensationalizing the impacts based on such hypothetical predictions on several processes, including agriculture.
The IPCC, UN, Media, agencies like World Bank, Oxfam, CGIAR, etc. are using Climate Change as synonymous to Global Warming. This is not so; Global Warming is one component of Climate Change in which natural variations play vital role with extremes forming a part. The World Meteorological Organization of United Nations (WMO/UN) published a manual on “Climate Change” as far back as 1966. It dealt with methods to separate man-induced variations from natural variations. Natural variations are beyond human control, only we have to adapt to them. On the contrary, the impact of global warming must present a trend, increasing or decreasing to ascertain its impacts. The IPCC and UN bodies are talking about individual events that are part of natural variations as associated with increased global temperatures.
These are highlighted by the media with misleading headlines. By attributing the impacts associated with normal climate extremes within the limits of Climate Normals and rhythms present in meteorological parameters to global warming is dangerous.
Now the IPCC itself has agreed that 100% of the raise in global temperature is not associated with the raise in Anthropogenic Greenhouse gases and agreed that around 10% is contributed by urban-heat-island effects – this contributes to rise in night time temperature and lower layers of troposphere temperature. These are localized effects.
Same is the case with changes in land use and land cover, known as Ecological changes. The majority of meteorological stations are in urban areas and thus urban-heat-island effect is going to be added to global warming component and on the contrary meteorological stations are sparsely located in rural areas that generate cold-island-effect due to increased activity of irrigated agriculture and spread of irrigation reservoirs is not going in to global warming component – however, this may create a trend in precipitation at local and regional scales like that seen in AP precipitation.
In all around 50% of raise shown under global warming is influencing the local and regional aspects but not national and global aspects like sea level raise, ice melt, etc. Southern hemisphere with less number of urban areas, with less ecological changes and with more area under ocean waters showed lower temperature raise over the average pattern. In the case of Northern Hemisphere with more urban areas, more ecological changes and with less area under ocean waters showed higher temperature rise over the average pattern.
It is a fact that in the last 17 years there has been no significant change in temperature, including ocean temperatures; ice melt in Arctic and Antarctic zones are within the standard deviation around the mean; no change in precipitation – monsoons, etc. In association with local conditions and natural disasters the sea levels show rises in some places, falls in some places, and no change in the majority of places.
Ice is confined to outside the South Polar Ring and inside the North Polar Ring. That means South Polar ice melt is the true reflection of global warming impact on ice melt. At present it is not showing any melt in the Southern Polar zones. The Southern Polar zones are on the contrary building ice. North Polar zones are losing the ice but this is within the long-term standard deviation around the mean – within the accepted statistical terms. In the North Polar zone, impacts other than climate are also contributing to ice melt.
Alaska shows a large fall in sea level. Along the USA coastlines, a large part showed a 0 to 1.0 feet fall, this may be associated with human activity along the coastal zones, tidal erosion, etc. [San Francisco airport does not show any sea level rise]. Also, error variations are far higher than the estimated rise, which is not statistically significant. In addition, all these localized natural variations play a vital role – even the global temperature showed a 60-year cycle – sine curve. Cyclonic activities including Hurricanes and Typhoons – and precipitation, all present cyclic variations. With the growing population of the planet, and building more structures in the path of cyclonic storms – that includes Hurricanes & Typhoons – and Tornadoes, and thus this makes ordinary storms more damaging.
Food production, food security & nutrition security are not affected by global warming. Floods and droughts are part of rhythms in precipitation, however, their impacts are modified by agriculture technology and ecological changes. Food includes not only agricultural products but also include several others such as Dairy products, Poultry products, Sea & Water products [fish & prawns], Animal products [meat], etc.
These are affected by agriculture technology and pollution components and not by global warming as crops adapt to temperature regimes which is evident from extremes in temperature given under climate normal data. These, along with ecological changes are the major contributors of destruction of biodiversity – on land, in water including oceans. Pollution, more particularly from new agriculture technology, is the major source of health hazards globally and not associated with Global Warming. Global Warming is in fact a brain-child to counter the Environmental Movement against pollution, more particularly agriculture pollution, initiated in late 60s and early 70s.
In the agricultural perspective, these matter: stop wastage of food; plan better utilization of water resources; shift from chemical inputs to organic inputs technology that help reducing pollution and public health aspects; do not forget that the losses due to intense weather systems increase with the population growth. Globally, cold waves are affecting many more vulnerable people than heat waves. Wild fires have nothing to do with global warming. Dry weather helps spread of fire over wet weather, which is nothing to do with global warming.
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Dr. S. Jeevananda Reddy
http://library.wmo.int/opac/index.php?lvl=author_see&id=5178