Three times the size of the United States, the ozone hole has continued to grow over the last few weeks and is set to reach a maximum size in late September.

The consequences are likely to be serious and far-reaching.

WMO Professor Obasi warned on Wednesday that the most immediate threat to humankind relate to “increased variability in the intensity and frequency of storms … floods and droughts, heat waves in major urban areas and the impact of sea-level rise on low-lying coastal regions”.

Decade of evidence

Over the last ten years, the number of disasters of hydrometeorological origin has increased significantly, Obasi says.

Worldwide, recurrent drought and desertification seriously threaten the livelihood of over 1.7 billion people who depend on land for most of their needs. 

The 1997/1998 El Ni?o event, the strongest of the last century, is estimated to have affected 110 million people and cost the global economy nearly $100 billion.

Insurance

Statistics compiled from insurance companies for the period 1950-1999 show that the major natural catastrophes caused estimated economic losses of nearly $1 trillion. 

A leading reinsurance company estimates global warming impacts could cost an additional $300 billion annually by 2050.

Worse, the size of the hole has not decreased despite reductions in ozone-depleting chemicals.

Long-term hope

However, measurements show that most of these chemicals are decreasing in the lower atmosphere and appear to have reached their peak in the critically important layer in the stratosphere.

There is a delay in chemical cleansing the ozone layer, and it is expected to require years before the stratosphere returns to pre-ozone hole conditions. 

Complete recovery of the ozone layer will require the enforcement of international agreements for many years to come.