Climate change

What is happening and why

If you were to walk in the New Guinea highlands 30 years ago, and make the same trip again today, things would probably look fairly similar. But if you had logged the temperature at that time, and compared it to the temperature today, you would probably notice something odd: slightly warmer conditions.

Meteorological data from the highlands that span the last 35 years are extremely rare. However, sheds of evidence from several mission stations, coffee plantations and mining companies show the same worrying story: one where the air has been warming some 0.3 °C every decade since the early 1970s.

If these data are confirmed, we would be dealing with a warming rate that is 5 times the previous estimate for the region - among the fastest in the world. ¹ It will take further scientific climate monitoring in the highlands to get a clearer picture of what is indeed happening in the local climate.

Why is this happening?

We need to travel far from the remote highlands of New Guinea to understand why there’s a change in the air temperature. In fact, all the way to industrialized and developing countries, which are releasing ever-higher amounts of carbon dioxide (CO₂) and other greenhouse gases into the atmosphere.

Because of the excessive quantity of greenhouse gases that are released into the air, global temperatures are expected to rise by 1.4 - 5.8° C by 2100. Already, data shows that temperatures have risen by 0.6° C above pre-industrial temperatures.² And in the montane forests of New Guinea, these trends are already being felt.

Glaciers, a slow-motion disappearing act

The areas that show the highest level of warming are at high altitudes, such as Mount Jaya, at 5,030 m New Guinea’s highest peak. There, glaciers have been in retreat for almost a century. Aerial photographs taken by the mining company Freeport, which operates in the area, show that glaciers have receded by 300 m compared to when they were last mapped, in the 1970s.³