Weathering the storm

As per a recent study by U.S. scientists, the proportion of tropical cyclones reaching categories 4 or 5 has risen from 20 in the 1970s to 35 in the 1990s over the globe.

In the last 50 years, cold days, cold nights and frost have become less frequent, while hot days, hot nights, and heat waves have become more frequent.

In India, an increasing trend has been observed in monsoon rainfall in the west coast, north-western region and northern Andhra Pradesh.

Certain pockets in central India have experienced increase in heavy precipitation and decrease in number of rainy days.

8226; What are the main instances of extreme weather conditions in the last few years?

2002: Drought in India. July is generally the wettest month of the year but in 2002 it turned to be the driest in recorded history since 1877.

2003: UK records its highest ever temperature. France has the warmest summer on record. Temperatures in Russia dip as low as -450C. Moscow receives rainfall in June for the first time since 1963.

2004: Severe drought condition in western U.S. Long term drought across Africa. Excessive rains in Brazil and United Kingdom.

2005: 14 hurricanes in U.S., two more than previous record in 1969. Snowfall in UAE in January. Mumbai gets 94.4 cm rain in just eight hours on July 26.

2006: Worst drought in a century in Australia.UK gets hottest September in 277 years. Malaysia inundated with heaviest rainfall in 100 years. Moscow8217;s mid-December temperatures highest in 108 years.

2007: Intense rainstorms in Indonesia. Worst drought in 30 years in north China.

8226; Is it related to global warming?

Some meteorologists believe that such extremities could be part of natural climate variability. But a majority of them tend to agree that as the world warms, some extreme events which are directly linked to warming, are expected to increase.

There is a tendency to relate every extreme event with global warming. It is important to note that it is not possible to link any particular weather or climate event definitively to global warming. The causal linkage, if any, can only be determined through statistical analyses of long-term data.

8226; Can such extremities be controlled?

There is no way that we can prevent these disasters from happening. But, we can soften their impact. For example, a green belt in the city can make the heat wave less felt by the people. Similarly improved predictions and advance warnings on severe weather events can help people prepare better.

8226; If we stabilized greenhouse gas emissions at today8217;s rates, would global warming stop?

No. As of now we emit more carbon dioxide than natural processes like photosynthesis and absorption by oceans are able to remove. Therefore, stabilising at today8217;s rates will still mean that 8220;deposits8221; would continue to exceed natural 8220;withdrawls8221;.

8226; If we stop emitting greenhouses gases now, would global warming stop?

Not right away. The Earth8217;s surface temperature does not react instantaneously to the energy imbalance created by rising carbon dioxide levels. Even if all emissions were to stop today, the Earth8217;s average surface temperature would climb another 0.6 degrees or so over the next several decades before temperatures stopped rising.

8226; What can we do about global warming?

Reduce energy consumption and use efficient energy sources.

Production of more energy from nuclear and renewable sources.

Capturing carbon emitted by power plants and storing it underground.