Report warns of growing Australian tropics

What is the State of the Tropics report?

The State of the Tropics report was produced by 12 research institutions from across the world, including James Cook University, providing an in-depth assessment of the Tropics as an environmental and geopolitical entity in its own right.


Burmese opposition leader Aung San Suu Kyi has launched the report in Rangoon, with global experts responding in Singapore, Cairns and Townsville.

What regions make up the Tropics?

The Tropics include Papua New Guinea, Central and Southern Africa, Northern Africa and the Middle East, South Asia, South East Asia, Caribbean, Central America, South America and Oceania. Australia forms part of the Oceania region, with 5.7% of the population in the Tropics.

What are the key findings?

The Tropics is not only changing rapidly, its influence and impact on the rest of the world is set to dramatically rise in coming decades.

“A child born today in Sydney could well be retiring in a birth place that will be climatically similar to contemporary Brisbane.”

The report estimates that by 2050, half of the world’s population and 67 per cent of the world’s children under 15 years of age will be living in the Tropics.

In economic growth, the Tropics has outperformed the rest of the world over the past 30 years and is now estimated to represent 18.7 per cent of global economic activity.

Climate change has the potential to disproportionately affect the Tropics through impacts on human and food security, renewable water availability, rising sea levels and vector borne diseases.

Climate change: tropical expansion slower than expected

The Tropics is continuing to expand as the Earth warms, but at a slower rate than earlier thought.

Recent research indicates the primary causes of tropical expansion are likely to be greenhouse gases, black carbon, aerosols and other human-made pollutants.

There are significant implications for regions which currently border the equatorial zone that may experience an increase in extreme rainfall, resulting in flooding and the displacement of communities and increased incidence of disease.

Experts believe such tropical expansion could see Sydney’s climate later this century become similar to Brisbane today.

“So a child born today in Sydney could well be retiring in a birth place that will be climatically similar to contemporary Brisbane,” said Professor Steve Turton, School of Earth and Environmental Sciences, James Cook University.

The Oceania region has the lowest CO2 emissions but the highest per capita CO2 – equivalent emissions of greenhouse gasses in the Tropics. A large proportion of this is attributable to Australia and Hawaii, because when they are excluded, the per capita emissions are the third lowest in the Tropics and well below the world figure.

Coral reefs: under threat 

Threats to coral reef systems have increased markedly in recent years with over half the reefs in the Tropics now considered to be at medium or high risk of damage

The Oceania region has 47 per cent of the world’s coral reefs with Australia accounting for 15 per cent and New Caledonia 13 per cent.

Threats to corals have increased sharply since 1988, but only Oceania and South Asia had more than 40 per cent of coral reefs at low risk. In Australia, 67 per cent are considered at low risk from local threats.

Health in the Tropics: life expectancy increasing

Life expectancy has increased across all regions of the Tropics in the past 60 years, but still remains well below the rest of the world. There have been significant decreases in maternal and child mortality rates since 1950, but globally the figures are still not good. The region accounts for 76 per cent and 72 per cent of mother and child under-five deaths.

In 2010 the Tropics represented 96 per cent of malaria cases and 99 per cent of deaths from malaria, with Central & Southern Africa having the greatest burden.

The Oceania region is the only part of the tropics to have not seen a decrease in tuberculosis incidence. TB incidence has increased since 1990 in the Oceania region due to increasing rates in Papua New Guinea and three small Pacific Island Nations.

Education: Youth literacy problematic

Since 1980, schooling of adults has almost doubled in the Tropics and youth literacy rates have increased in all regions expect for Oceania since 1990. The youth literacy rates decreased in this region slightly due to PNG, where increase in the literate youth population didn’t keep pace with the increase in the youth population.

Adult literacy rates have increased faster in the Tropics than the rest of the world, but are still considerably lower. The unemployment rate is also cyclical and influence by economic growth, with a small increase in 2009 during the global financial crisis.

Crime and corruption: considerably higher rates

The homicide rate in the Tropics is considerably higher than in the rest of the world, with a rate of 14.5 per 100,000. That’s compared with a rate of 5.6 per 100,000 in the rest of the world. But within the tropics there is a vast deal of regional and national variation.

In South America the homicide rate was 32.9 per 100,000 compared to 5.1 per 100,000 in South Asia. Compared to the rest of the world the Tropics received lower scores for a range of governance indicators, indicating higher rates of corruption.