Changing climate of Bangladesh

The global climate is changing, and Bangladesh is not spared. Bangladesh Meteorological Department (BMD) and Norwegian Meteorological Institute (MET Norway) have collaborated since 2011, and in 2016 we co published a report on the current status of the climate of Bangladesh called Climate of Bangladesh. The same cooperation has resulted in a new report that was published this year. The new report goes beyond the baseline of today's climate and explores detected changes in the Bangladeshi climate for the last 40 years through the weather observations in Bangladesh. 

In this report, a homogeneity test of the Bangladeshi observations is performed, and shows that data from about 1980 has an acceptable level of homogeneity. Based on this, trends have been calculated for maximum and minimum temperature, daily temperature range, precipitation amount and frequency, and sunshine hours and cloudiness. The major picture is that in Bangladesh all of these elements show clear signals of change consistent with the global pattern of climate change. This analysis also indicates regional differences with a more rapidly warming climate in the north and east of the country. 

More details of the effects of the changing climate on heatwaves and cold outbreaks have been analysed. This analysis shows a tendency to later onset of the heat, and, more worryingly, a tendency of increased heat waves in the monsoon season. A similar analysis of heavy to very heavy rainfall does not reveal any clear shift.

The monsoon is very important for the agricultural sector, and has received special attention in the report. The dates for the onset of monsoon, as documented by meteorologists at BMD, is published, and a small analysis shows no significant change in onset day. The rainfall in the monsoon is changing, and a pattern of decreased rainfall in most of the country is emerging but not statistically significant.

The report is co-published at the websites of BMD and MET Norway