RIYADH: Even if the national climate plans of countries worldwide are successful, carbon emission levels will cause catastrophic effects by 2030, according to the UN’s climate chief. Current plans would result in emissions of 51.5 gigatonnes of CO2 equivalent by 2030 — only a 2.6 percent reduction on 2019 levels. These emissions would lead to severe human and economic consequences worldwide, according to a statement issued on Monday by Simon Stiell, executive secretary of the UN Framework Convention on Climate Change.