Over the last three years, the Rohingya refugee camps in Cox's Bazar and Teknaf have been telling us many stories of failures, successes and uncertainties.

These camps are a painful symbol of Myanmar's atrocities against its own citizens, making them stateless. The government of Bangladesh, the United Nations (UN) agencies and their partners, and numerous donors, however, have managed to offer these 1.1 million people shelter, food, water, sanitation facilities, health services, protection from violence and trafficking, as well as education, energy supply, and safety from natural hazards. However, these 34 refugee camps still remain a failed story of humanity, full of uncertainties around return of the Rohingyas, including their 438,000 children, to Myanmar.

The Rohingya refugee crisis not only hurts our dignity as humans, it has also made a deep scar on Bangladesh's efforts towards environmental conservation. According to a report by the Ministry of Environment, Forest and Climate Change of Bangladesh, as of early October last year, the overall ecological damage of this refugee crisis cost about USD 285 million. Almost 60 percent of this damage was due to the loss of biodiversity. Other losses include destruction of natural and planted trees as well as uprooting of trees. That report also noted that the refugee settlements occupy about 2,500 hectares of forest land, while another 750 hectares of forest were destroyed from firewood collection by the refugees.

Despite this worrying situation, the government and UN agencies have taken some commendable actions to improve the overall environment in the refugee camp areas. One of those is distribution of Liquified Petroleum Gas (LPG) cookers to the refugee families.

LPG distribution was started in 2018 to reduce the huge pressure on Cox's Bazar's remaining forests from fuelwood collection. At the end of 2019, a study by UNHCR-IUCN-East West University showed that the LPG supply had reduced 80 percent of firewood use by refugee families. This success made LPG distribution one of the major activities of the UN agencies in 2020, and by April, they brought all 188,000 refugee families under this activity. This indeed has significantly reduced the pressure on the adjacent forests and their biodiversity.

But slowing down forest destruction is not enough to rebuild the severely degraded ecosystems of Ukhiya and Teknaf. We need appropriate actions on the ground to restore the damage caused by the refugee crisis—we need to apply nature-based solutions (NbS) for that.

NbS are different activities we do to protect, conserve and improve natural and modified ecosystems. But, in the present refugee crisis, it may refer to the restoration of damaged ecosystems, like the hills, forests and hilly streams, and to the protection of remaining habitats from destruction.

In the Cox's Bazar-Teknaf peninsula, NbS have to be applied in such a way that the altered ecosystems restart giving the services they are supposed to give us—a healthy, green environment to breathe in, stable hill-slopes that are no longer susceptible to landslides due to heavy rain, return of biodiversity to an area that became barren in late 2017, sufficiently recharged groundwater, and hilly waterways smoothly carry rainwater without getting too silted up.

Although they are not calling them NbS per se, the UN agencies, their partners, and the Bangladesh Forest Department (BFD) have taken some commendable NbS initiatives to improve the overall environment of the refugee camps. In 2018 and 2019, for example, they reforested about 350 hectares of camp area involving the refugees and host community. They followed the protocol developed by the Food and Agriculture Organization of the United Nations (FAO) and BFD. Despite the Covid-19 pandemic, the plantation programme has started in August to replant a couple of hundred hectares of camp area maintaining social distancing and other safety rules.

Innovation is also going on alongside plantation. Last winter, FAO piloted dry season planting techniques in Teknaf. A 100 percent survival rate of the saplings in the experiment plots suggests that tree plantation in refugee camps would also be possible in the rainless winter months.

Another NbS widely implemented in the camps is stabilising the hill-slopes to avoid devastating landslides. Site Maintenance and Engineering Project (SMEP), a multi-agency partnership, has been creating terraces on tens and thousands of square metres of slopes with bamboo fences, geotextile and reinforced concrete rings, and greening the open soil with vetiver and other grasses and legume saplings, to avoid erosion.

On smaller scales, since 2019, UNHCR and its NGO partner CNRS have been piloting several NbS in the camps, including restoration of hilly streams with banks stabilised with vetiver and vadail grasses and excavation of water reservoirs to reduce pressure on groundwater.

In addition to these short-term, site-specific actions, there is a need for long-term, holistic approaches to restore the degraded landscape of Cox's Bazar. Realising that, the Center for Global Development, BRAC, and The Nature Conservancy advocated for a long-term "forest landscape restoration" (FLR) approach, a type of NbS. While their suggestions are comprehensive and practical, and can effectively engage Bangladeshi host communities outside the camps, involving refugees is difficult in many proposed activities given the uncertainty around refugee repatriation, their possible relocation inside Bangladesh, and the government's position on involving refugees in long-term activities with benefits.

The piloting, innovations, successes and challenges around different NbS we have tried in Rohingya refugee camps over the last three years bring in three opportunities before us.

First, the International Centre for Climate Change and Development (ICCCAD) and the University of Oxford have recently launched the NbS Bangladesh web portal (www.nbsbangladesh.info) and the NbS Bangladesh Network of experts and organisations working on NbS. These two new initiatives are giving us the opportunity to capture and widely share Bangladesh's NbS experiences in the refugee crisis. Bangladesh can lead the world on how environmental conservation is possible through NbS even in humanitarian crises.

Second, over the last year or so, NbS has received significant global attention as a practical approach to deal with challenges, like climate change and natural hazards. This February, 20 leading environmental organisations proposed guidelines to make NbS better and successful. In July, the world's largest environmental network IUCN launched the Global Standard for NbS to avoid misuse of the NbS concept. The government of Bangladesh, UN agencies, and their partners now need to recognise these developments as they implement NbS in the refugee camps. Such realisations can strengthen NbS, and thus nature conservation, in the ongoing refugee crisis.

Finally, over the past couple of decades, Bangladesh has been practicing NbS by sustainably managing, protecting and restoring its coasts, forests, hills and wetlands with local communities. Our NbS experience in Cox's Bazar has further shown the superb capacities of Bangladeshi academics, practitioners and administrators to design, implement, innovate and assess NbS projects and related policies. We therefore need to recognise our strengths and start relying upon our own experts, instead of international ones, in nature conservation.

Dr Haseeb Md Irfanullah is an independent consultant working on environment, climate change, and research systems. His Twitter handle is @hmirfanullah