In 2020, climate disasters overstrained Bangladesh. First, the cyclone Amphan with winds up to 150 kmph crossed 26 districts from South to North on May 20. Then from July to August, the devastating monsoon flooded 33 districts of the country. These two events in only a couple of weeks suggest that climatic shocks' frequency and severity are on the rise due to climate change in one of the world's most climate-vulnerable countries.

The human and economic consequences of these climatic events are disastrous. Amphan killed 26 persons, damaged 149,000 hectares of agricultural lands, and affected more than a million people. A few weeks later, the floods submerged 159,000 hectares of agricultural land, affecting 1.2 million farmers directly and five million people in total. Unfortunately, the Covid-19 crisis and the resultant lockdown added to the climatic challenges by slowing down relief interventions, putting the displaced populations at risk of contracting the virus and increasing poverty for the most vulnerable.

Bangladesh contributes 0.22 percent of global carbon dioxide emissions, yet the country's engagement in addressing climate change is exemplary. In September 2015, in its Intended Nationally Determined Contributions (INDC) under the United Nations Framework Convention on Climate Change (UNFCCC), the country committed to reducing its Greenhouse Gas (GHG) emissions unconditionally by five percent by 2030 and conditionally up to 15 percent by 2030, if appropriate international support is provided. Building on previous targets for renewable energy, solar pumps for irrigation are one of the tools aiming to reduce GHG emissions in the agricultural sector by replacing diesel pumps as part of the country's engagement.

Early results from the Solar Irrigation for Agricultural Resilience project implemented by the International Water Management Institute in partnership with the Infrastructure Development Company Limited (IDCOL) in Bangladesh indicate that solar irrigation pumps (SIPs) can meet the challenge of climate change: while it tackles climate change, it also potentially reduces poverty. Solar irrigation mitigates climate change by minimising GHG emissions and allowing farmers to adapt to the consequences of climate change. In addition, the SIPs are resilient to climatic and economic shocks and benefit vulnerable farmers. It means a win on four fronts of climate change: mitigation, adaptation, resilience, and equity.

There are in Bangladesh 1,969 operational solar irrigation pumps. Most of these (1,515) have been set up by IDCOL in areas with alluvial aquifers, located in Rangpur and Rajshahi divisions in the north-west and Khulna division in the south-west. From a survey conducted in 2020, SIPs irrigate an average of 7.6 hectares and provide irrigation to 42 farmers each, but they have the potential to serve even larger areas. The fee-for-service model has the potential to strengthen equity in access to irrigation services. Instead of privately owning a pump, buying water or renting a pump from neighbours, all the farmers from the SIP command area benefit from the same irrigation service at the same tariff. This tariff is set at a lower level than diesel-operated irrigation to benefit a larger number of vulnerable farmers. In the national figures, 24 percent of farmers in Bangladesh are tenant farmers, but from a representative sample of the SIPs which provided irrigation during the last two kharif seasons (one of the two distinct cropping seasons in Bangladesh), 36 percent of the farmers' beneficiaries were not owners of the land cultivated and irrigated, and were either sharecroppers (10 percent) or leasers (26 percent). In addition, 62 percent of them were tiny farmers cultivating less than 0.5 acres of land.

Second, solar pumps tick the box of climate change mitigation by minimising the risk of GHG emissions and climate disaster globally. Irrigation in Bangladesh depends on more than 1.4 million diesel pumps. According to our estimates, 3.5 million metric tons of carbon dioxide are emitted per year from the diesel pumps used for irrigation, corresponding to 4.4 percent of the total emissions. Solar irrigation, therefore, has the potential to slow down rising GHG emissions from the agricultural sector and ensure that the increase in energy access for farmers comes from renewable sources.

Third, solar pumps are also tools that can be used by farmers to adapt to climate change and minimise the losses from climate disasters such as those the country went through last year. When cyclones or floods hit, kharif harvests are at risk, but it is equally true in cases of droughts or irregular rains. Reducing the risks for the other seasons becomes, therefore, essential for food security and poverty alleviation. The solar pumps installed in Bangladesh are designed to irrigate the water-intensive boro paddy cultivated in the dry season, but also to secure the harvests of more diversified cropping patterns. Hence, 49 percent of the SIP's gross irrigated areas throughout the year is cultivated with boro paddy, but a sizeable 22 percent is also cultivated with non-rice crops including maize, wheat, potatoes, tobacco and jute. This allows farmers to secure their paddy harvest during the dry season and diversify their cropping patterns, while accessing irrigation at a lower cost than with diesel operated pumps.

So, solar pumps have the potential to mitigate climate change and help farmers to adapt to climate changes, yet this prospect would be ruined in the case of climate shocks damaging the equipment, and if the service delivery became vulnerable to other shocks. The year 2020 has brought, in that sense, useful lessons. Out of a sample of 61 representative SIPs surveyed, only two among those located in Khulna had some damages due to the cyclone, and two located in Rangpur saw their command flooded. The Covid-19 pandemic also had limited effects on the operation of the solar pumps. Despite restrictions of movement during that period and challenges in selling the rabi harvest in 18 percent of the SIPs, the irrigation services were operational during the dry season. As a result, 92 percent of the due fees were collected by operators for the 2020 rabi season.

Ultimately, the objectives of climate change mitigation, climate adaptation, resilience to shocks and equity can converge by promoting solar irrigation where groundwater resources are renewable and not affected by arsenic contamination. Bangladesh, so far, has fallen short of the targets set in the 500 MW Solar Power Generation Plan and the Renewable Energy Policy of Bangladesh, but a push towards solar irrigation would help catch up and put the country on track.

Marie-Charlotte Buisson and Archisman Mitra are researchers at the International Water Management Institute (IWMI-CGIAR).