Dear Krishna,

It is not like that the climate change is going to cause excessive rainfall and drought at a same place. Either both are interrelated however It is predicted that the climate change is going to cause wetter place become more wet and dry places will be more stressed by the drought.

Hi,

    If I understand your question correctly, I believe this is possible. Increase in variability will result in increase of both sides of the distribution. 

Cheers

Dear Krishna,

Second things is that, at wetter places the intensity of the rainfall will be more, but event will be less so it may also cause the drought and rainfall to become higher at a place if your compare it with the normal.

Dear Krishna,

It depends on the availability of the moisture content in the air. If moisture content is high in the atmosphere, more evaporation and evapotranspiration will takes place which causes precipitation. On the other hand, if moisture is already less in the air and the temperature is rising, it may cause drought.

I think Krishna wants to correlate between change in any climate factors (temperature, humidity, ....) with weather events like drought and precipitation. Positive thinking indeed.

If you want to correlate between change in climate factors and precipitation, you may measure Standardized Precipitation Index (SPI) and compare with changed variables.

If you wish to Correlate between drought and change in climate factors for any region, you may measure De Martonne's Index of Aridity (De Martonne 1925).

First of all, you have to collect meteorological data for that region, you may prepare Sd (Standard deviation) from mean for mean maximum temperature or mean minimum temperature, calculate SPI and AI (DM). Compare them...

Thanks.

Siddiq

Dear Kenneth Sir,

I think Krishna wants to ask how climate change is responsible for rainfall and drought both.

'Excess of rainfall and drought in one place' is possible, these extreme events have been occurring in the same place but at different times, with climate change, the variability is projected to increase resulting in increase in intensity and frequency of the extreme events.

Thanks to all for your valuable suggestions

Krishna, I'm elaborating on what Leiw, Victor has already mentioned. Human accelerated Climate Change has two dimensions - (1) change in climate over a long period of time,such as, increase in global temperatures over 80 - 100 years, and (2) increase in variability / extremities in climate parameters. It is due to the second dimension that increase in extreme events of rainfall (deluge for extreme high rainfall and drought for extreme low rainfall) are related to climate change. And of-course both extremities can happen in same region at  short intervals, e.g., Monsoon season in central India in 2014 - it started sluggish with near drought like situation till 17 Jul. Then in early August there were heavy rainfall events leading to water logging. Both were detrimental for soybean crop grown in central India.

Kenneth - thanxs for the paper and your interjection. It is a real challenge to separate the secular changes and human induced changes in climatic extremes (frequency & intensity). Would luv to see some papers on how to separate the two if you know.

Rainfall in many places is subject to climate teleconnections such as the ENSO and Indian Ocean Dipole. These in turn are basically created by changes in the differential heating and cooling of the earth's surface (leading to pressure systems, winds and ocean currents). The increasing heat storage capacity of the atmosphere (because of greenhouse gas accumulation)has been thought to change these heating and cooling patterns at a grater rate over the past few decades. Hence, there can be changes in rainfall patterns at a place, with years of high rainfall followed by drought years. Local large-scale deforestation can also contribute to flash floods followed by reduced water availability over the dry season on the landscape.

Kenneth, I think global rates of temperature would perhaps not be sensitive enough to portray fluctuations at a certain place. My comment was more from a mechanistic perspective on the atmospheric energy budget that is changing owing to greater heat storage ( especially in the latter half of the 20the century and continuing), and thereby possibly changing the heating and cooling spatiotemporal patterns upon the Earth's surface from what was probably relatively uniform over the past several centuries.

Climate uncertainty is a major symptom of climate change. Global warming is the consequence of human activities as burning fossil fuels. One will need to understand the role of the parameters of climate models being either one dimensional or multidimensional models. One will see that albedo plays a main role in hating and or cooling the atmosphere and it varies with the latitude. In mixed models atmosphere is divided in layers taking into account local climate linked to ocean models that take into account currents, temperature and salinity. I will recommend the book: A Climate Modeling Primer, A. Henderson-Sellers and K. McGuffie, Wiley,

hello Kenneth, my comment is based on the orders of magnitude higher use of natural resources over the 20th century as compared to previous centuries going several millennia back, that are thought to  have led to the buildup of heat-trapping greenhouse gases in the atmosphere. Just a century ago, the first world cities did not have refrigerators and TVs and central heating/cooling systems and a myriad of appliances that take resources to build and run. Much of our food came locally, not packaged and imported from other continents. In the urban third world too, the per capita resource usage is going up. In my lifetime alone, I have seen a decline of fish diversity and abundance off the coast of India and Florida. Now that is not directly connected with GHG, I agree, but I mention that as an illustration of the fast rates of global change. Using single indexes such as temperature, or gas concentration are greatly inadequate to quantify changes in the earth's pressure and circulatory systems that are so complex that most circulation/rainfall models have tremendous uncertainty.

Kenneth. Yes, since the post war began the warming due fossil fuels use and began the systematic monitoring. You are right warming and cooling (Maunder minumum for instance) of the earth has happened long before. The Milancovitch postulates also have played main role in the earth climatic status, volcanoes, sun behavior (we are about to be in the solar maximum of cycle 24 th with a weak sunspots) ,etc. These facts add uncertainty to climate ( perhaps not weather).

Among others (aerosols, ozone), CO2 and the Sun played the largest roles in the early century warming,

Climate change for India and Pakistan will not be the immediate issue causing droughts and floods--it will be the Pakistan-Arabia Dust Cloud that will cause droughts and floods, and has been doing so for quite a long time, probably about 5,500 years or so.  

See https://www.researchgate.net/publication/250945222_The_Dust_Cloud_that_eats_Cyclones_and_Causes_Droughts_and_Floods and https://www.researchgate.net/publication/263505239_Pakistan-Arabia_Dust_Cloud_battles_with_Cyclone_Gonu_and_Gonu_loses_Third_look

In addition to the effects from the Dust Cloud,  India will suffer droughts because most of their Pseudomonas-host trees have been chopped down, except there are a few left in the Western Ghats that could be propagated and planted around the country to help produce regular rainfall.  

Article The Dust Cloud that eats Cyclones and Causes Droughts and Floods

Data Pakistan-Arabia Dust Cloud battles with Cyclone Gonu, and Go...

Interesting.............Good Discussion

Regards

Vinit