When world leaders, diplomats, campaigners and scientists descend on Sharm el-Sheikh in Egypt next week for talks on tackling climate change, don't expect them to part the Red Sea or other miracles that would make huge steps in curbing global warming.
Each year there are high hopes for the two-week United Nations climate gathering and, almost inevitably, disappointment when it doesn't deliver another landmark pact like the one agreed 2015 in Paris.
