Giving those affected by climate change a greater say in the selection and monitoring of aid projects would save lives

World leaders meeting for this year's climate conference in Durban will be under pressure to pool enough new funds to protect people from the floods, droughts and storms that climate change brings. With so many lives and livelihoods at stake, mostly among the world's poorest communities, they must make sure the funds are not only well spent, but accounted for.

When funds for flood defences in one small community in coastal Bangladesh were misused, sea walls were built too low and too weak. The villagers still live knee-deep in stagnant water that also ruins their crops. If the community had known what was happening – how much money was allocated and for what – it is unlikely they would have allowed sub-standard work.

This is a story of losing battles: our planet losing battles to climate change and corruption. It is a story that will become all too familiar in years to come, unless world leaders take action.

There is strong consensus that someone has to pay to reduce the emissions responsible for climate disasters like flooding and rising sea levels. By 2020, an annual $100bn is expected to flow to green technology, defences such as sea walls, and to helping people forced to abandon their homes.

Any climate agreement, and any new climate money, must give citizens a voice in selecting which projects to fund, allow them to monitor budgets, and show them who is responsible for making sure the work takes place.

When the agreed work is not carried out, citizens must be able to sound the alarm through hotlines or advice centres. Investing in accountability now will save money and lives further down the line.

The alternative is allowing resources to be hijacked and spending decisions to be made behind closed doors; permitting contracts to be given out to companies without the scrutiny that prevents bid-rigging, and work to be done without quality control or regular audits.

This is what can happen when unprecedented sums of money take a confused journey from international organisations, each with their own rules on reporting, through government departments to private companies. Sometimes we have no way of knowing what was spent and why, and who is ultimately accountable for a project's success or failure.

Leaders in Durban can start with the proposed green climate fund, which should distribute the bulk of all climate money. The fund already promises to allow citizen consultations, independent monitoring and corruption investigations. These are great advances, but it remains to be seen whether leaders at the climate summit vote for a fund that hears and responds to people on the ground.

We all fear what the consequences of taking too long to tackle climate change will be for our children and grandchildren. In Bangladesh, they already know the consequences. They live them every day: in ruined crops and flooded homes, in the saturated ground under their feet.

It is not too late to help people who are already feeling the effects of climate change, however. And the place to start is Durban this week. If leaders act, and people are empowered to hold their leaders to account, the flood defences will be high and strong enough to keep out the water.

• Cobus de Swardt is managing director of Transparency International