The Brazilian floods that have claimed over 600 lives is the deadliest natural disaster to have hit the country. This comes barely months after an unprecedented drought hit the Amazon region when water levels in the river's tributaries fell drastically.
Torrential rains inundated a heavily populated, steep-sloped area about 40 miles north of Rio de Janeiro on Tuesday and Wednesday, triggering flash floods and mudslides. The disaster had claimed 610 lives at the last count. Rainfall amounts of approximately 300 mm (12 inches) fell in just a few hours in the mountainous regions. The toll makes the current floods Brazil’s worst natural disaster in history. The total casualties in the 1967 floods was 785. This one, however, is the deadliest single-day disaster.
Floods and mudslides are not new to Brazil. Yet, this is the second major calamity to have hit it in less than a year. Floods and landslides near Rio in April last year claimed the lives of 246 people. Over 80 people died last January during a similar disaster earlier. Another 40-odd people died after rains flooded swathes in the northeastern part of the country in June.
Only a few months ago, the Rio Negro or Black river, one of the most important tributaries of the Amazon, fell to its lowest level in over a century,. What followed was a drought that ravaged tens of thousands of rainforest inhabitants. Nearly half of Amazonas state's 62 municipalities declared states of emergency, according to the Guardian.
What Brazil is now witnessing is what climate change scientists have been warning about for years.
In December, an international index had warned that around two-thirds of countries would become highly vulnerable to climate change by 2030. The Climate Vulnerability Monitor had looked at estimated effects of climate change in four key areas: health; weather disasters; human habitat loss from rising seas and desertification; and economic stresses on natural resources and other relevant sectors. By 2030, if no action is taken, 132 countries will register an overall factor of high vulnerability or above, the report warned.
Climate scientists have been insisting that the seesaw between mega-droughts and mega-floods will become increasingly common as human emissions intensify the hydrological cycle. This is a far-cry from the once-in-a-century-drought and the once-in-a-century-flood that humanity had known earlier. A team of Duke University scientists had even quantified this.
Meteorologist and former hurricane hunter Dr Jeff Masters talks of the “departure of temperature from average for the moisture source regions of the globe’s four most extreme flooding disasters over the past 12 months.” The near-record sea surface temperatures that he mentions are in sync with what has been suggested by the Duke climatologists.
Moving from the flood to the earlier October 2010 drought, forest scientist Simon Lewis had remarked, "We know from simple on-the-ground knowledge that the 2010 drought was extreme, leading to record lows on some major rivers in the Amazon region and an upsurge in the number of forest fires. Preliminary analyses suggest that the 2010 drought was more widespread and severe than the 2005 event. The 2005 drought was identified as a 1-in-100 year type event."
The fact that weather conditions are becoming extreme, and that frequency of these extreme weather conditions too is becoming shorter is borne by the Brazilian examples.