El Nino is famous for wreaking havoc on weather systems. But this time around, it's coming with extra muscle, causing crises from California to Peru and harming ecosystems around the world.

With the El Nino pattern, every few years, the winds change and the Pacific Ocean warms up, triggering droughts in places like Australia and floods in other parts of the world.

Hurricanes die down in the Atlantic, but appear more frequently in the Pacific. In the United States, winters get milder and wetter - and more people die from flooding than freezing.

The current El Nino period began this past March. It's the most forceful in more than a decade - and it's getting stronger. If the trand continues, this will be officially termed a strong El Niño by early August. It should then peak by the end of year, and retreat some time next spring.

From floods to droughts

But El Nino isn’t always predictable - nor are its effects.

In some parts of world crops are failing, while others are seeing a bumper harvest. California is waiting out a historic drought, as Peru prepares for devastating floods.

Bolivia, Colombia, Ecuador, Peru and Venezuela have already seen bridges, homes and hospitals destroyed by flooding. Crops have been ruined, and the mining industry has cut exports. All this is destabilizing emerging economies.

The situation is no less drastic in Indonesia. Droughts have hit the country particularly hard, affecting industries like mining, power, cocoa, and coffee.

Biodiversity pays a price

El Nino also has an impact on the natural world. Much of Australia's wildlife is adapted to the variable weather caused by El Nino - which appears to trigger green turtle breeding and changes in duck populations.

But on smaller and more isolated archipelagos like Ecuador's Galapagos Islands, it's a different story. Increasing rainfall has benefited invasive species, such as fire ants and tree frogs.

Native species not only have to cope with the changing weather, but also out-compete with generalist invaders.

The islands' marine birds - like the blue-footed booby, brown pelican and frigate bird - are struggling to feed their offspring, and are laying fewer eggs. Galapagos penguins and flightless cormorants are also heavily affected by the lack of food.

Marine ecosystems in decline

El Nino is causing sea temperatures in the Pacific Ocean to rise, contributing to corals bleaching. Increasingly strong waves relating to El Nino, along with exploding populations of sea urchins, are also having a devastating impact on the complex coral habitats that sustain a multitude of species.

Meanwhile, also related to sea temperature rise, the production of phytoplankton is decreasing, causing repercussions through the food chain so that even top predators like sea lions are going hungry.

Algal beds suffer too, affecting the animals that feed on them, including marine iguanas, turtles and many species of fish. Migratory species like sharks are being forced to move further offshore and forage in deeper waters.

The devastating impact of El Nino is clear. What has yet to be confirmed is whether the intensified phenomena related to human-caused climate change.