Biodiversity hasn't received the same attention as climate change, says Dr Andrew Hammond. Climate system is governed by physics and can be modelled quite effectively, he adds. But biodiversity is very complicated on multiple layers, which makes it hard to reach understandable targets for reducing carbon emissions in a global agreement with countries of around 200 nations. Countries now have until 2024 to hash out some of the details of this agreement - but they need to commit to scientific assessment before making any kind of progress towards reversing or correcting biodiversity loss.