LONDON — Analysts have raised forecasts for the prices of European Union carbon permits through 2019 to 2021 but warned the threat of a no-deal Brexit still hangs over the market in the short term. EU Allowances (EUAs) are expected to average 26.40 euros/tonne this year and 34.37 euros/tonne in 2020, according to a survey of eight analysts polled by Reuters. The forecasts were up 8.6% percent and 6.7% percent, respectively, from prices given in April, when the projections were for 24.31 euros in 2019 and 32.21 euros in 2020. The European Emissions Trading System (ETS) charges power plants and factories for every tonne of carbon dioxide they emit. Analysts said the price forecasts had been in