In 2019, the country had its hottest and driest year. Of course, it is global warming - plus two local weather phenomena.

Since November 2019, over 100,000 square kilometers have been consumed by fire in Australia. The current burning season, already considered one of the worst in decades, has killed at least 27 people and 1 billion animals , destroyed 2,000 homes and forced tens of thousands of Australians to leave their cities.

Large urban centers such as Melbourne, Sydney and the capital, Canberra, suffered from side effects, being covered by a thick cloud of soot. It is believed that last week, the smoke produced in the country covered 12 thousand kilometers and even reached the southern region of Brazil . You can see the movement of smoke in the atmosphere in these images released by NASA .

All eight states or territories of the country were somehow hit by the flames. The states of Victoria and New South Wales, however, were the most compromised, even declaring a state of emergency. There is no chance that the number of outbreaks will decrease on their own anytime soon: the southern hemisphere summer is just beginning.

Large forest fires and catastrophic consequences are common in Australia at this time of year, it is true. In the 2010 season, for example, 173 people died from the fires - this BBC chart shows the extent of material and human losses from previous fires. But the trend is that the record does not stay long. The reason? The global warming.

The intensity of the fire in recent weeks and the unusual number of fire outbreaks are a result of the record drought of 2019: last year was the hottest and driest since the early 20th century. Hot flashes that hit the country in December were the icing on the cake, making the thermometers go over 40 degrees and letting the vegetation dry - which facilitates the spread of flames. On December 19 of last year, the country reached the record mark of 41.9 ºC. Australia's average temperature increased by more than 1.5 ° C compared to the historical average.

Rising temperatures, however, do not tell the whole story. The intensification of burning in the region also concerns specific weather events that have been traversing the region.

The main phenomenon behind excess heat is the so-called positive Indian Ocean Dipole. Also known as El Niño Indico, the event appears when the ocean surface temperature is warmer in one half of the ocean and cold in the other band. The difference between these temperatures is estimated to be the largest in the last 60 years.

The dynamics of winds also have their fault in the registry office. When South Ring Mode, the air mass surrounding the Antarctic continent, is in its negative phase, there is higher atmospheric pressure in Australia. This makes the climate even drier.

This climate combo intensifies the heat and the absence of rainfall in the central and southern parts of Australia: with drier vegetation there is less evaporation, and the flames spread faster. As a result, the average rainfall in the country in 2019 was 40% below normal . The tendency is for rising temperatures to make phenomena such as burning even more frequent and intense.