Filippo Giorgi of ICTP’s Earth System Physics section kicked off the discussions with an overview of the evidence for and effects of climate change. In addition, he highlighted the effect that the Earth’s changing climate is having on freshwater resources – especially the melting of glaciers, which currently account for more than 60% of the planet’s freshwater reserves (albeit as ice). He also noted – given the ‘Save the Food’ theme of Trieste Next – that humankind’s largest requirements for water are in the agriculture sector, and that producing a kilogramme of beef or chicken requires thousands of litres of water compared to producing a kilogramme of crops such as wheat, vegetables or potatoes.

In her presentation, Lidia Brito, director, Division of Science Policy and Sustainable Development, UNESCO, continued this theme, noting that the global population is expected to rise from the current seven billion people to nine billion by 2050. “To accommodate this increase,” said Brito, “we need to build the equivalent of one city of one million inhabitants every week.”

In other words, she continued, we need to start thinking now about solutions for the future. “Science should not be just inter-disciplinary, but also more integrated,” she argued. “It needs to take into account not only the environment, but also societal needs and economics.” And she challenged scientists to become activists – in the sense that they need to use their research to make a difference to raising people out of poverty via sustainable means.

The afternoon’s third speaker, climate specialist Jaroslaw Mysiak of the Fondazione Eni Enrico Matei (FEEM – also a partner in the EU-funded CATALYST project) described his research on the expected impacts of climate change in various developing countries. In Mauritius, for example, because of the unsustainable pattern of development around coastlines, it is estimated that future storm surges – predicted by climate models – will cause damage to the nation’s gross domestic product (GDP) in the range of 20-30%,  a situation that is clearly not sustainable. Likewise, in Nigeria, Mysiak revealed that there may be short-term gains in crop yields associated with increased temperatures and carbon dioxide concentrations. However, in the medium to long term, these gains will be more than countered by other limits to growth such as the requirement for water. 

Indeed, such comments brought the discussions full circle as Filippo Giorgi had already highlighted that although overall precipitation levels may not change, the rain that does fall will be more sporadic and come in more powerful downpours, making it difficult to retain the water for irrigation and also leading to more serious erosion of top-soils. In between, ‘normal’ dry periods will more frequently extend into droughts.

“The world is becoming more and more connected,” summarized Brito. “What we do locally has a global effect, and what we do globally has local effects.”