Historical emissions are based on the Second National Communication in the text and in figure 3.1 (Royal Government of Bhutan, 2015). The GWP is not specified in the Second National Communication but the document provides a breakdown of GHG gases that indicates the GWP is SAR. The Second National Communication provides sectoral historical data between 1994 to 2009. The CAT uses the revised 1994 data reflected in the Second National Communication. Data for 2013 is from the NDC.
The GWP is not specified in the NDC, however, the CAT assumes it is SAR, and consistent with the Second National Communication. The NDC data is converted to AR4 assuming the same percentage breakdown of each GHG gas reported in the Second National Communication for the year 2000. The NDC does not specify emissions from the agriculture sector, but the CAT calculates the agriculture sector by deducting emissions from other sectors from the total emissions. Interpolations are used for unreported years.
LULUCF emissions, when included, use data from the Second National Communication with interpolations for unreported years. Beyond 2000, the CAT applies growth rates from the Food and Agriculture Organisation of the United Nations (FAO) to estimate historical LULUCF emissions to 2017 (FAO, 2019).
For all emissions data prior to 1994, we applied the growth rate from 1994 onwards to extend the data series to 1990.
NDC and other targets
As the target is to remain carbon neutral, Bhutan must keep emissions below the level of the net LULUCF sink. We assume LULUCF emissions will remain constant through to 2030 at -6.3 MtCO2e, based on 2013 levels as the last historical data point.
Current policy projections
The CAT bases the current policy pathway on a reference scenario from an Asian Development Bank (ADB) report (ADB, 2013b). We applied the growth rates from the ADB “reference” scenario to the historical emissions up to 2030. We then deduct the emissions reductions potential from the Energy Efficiency Roadmap (Dept. Renewable Energy, 2019).
We applied a novel method to estimate the COVID-19 related dip in greenhouse gas emissions in 2020 and the development through to 2030. The unclear severity and length of the pandemic creates a new level of uncertainty for current and future greenhouse gas emissions. We first update the current policy projections using most recent projections, prepared before the pandemic (as described above).
We then distil the emission intensity (GHG emissions/GDP) from this pre-pandemic scenario and apply to it most recent GDP projections that take into account the effect of the pandemic.
The CAT used GDP based on a number of sources to estimate realistic pre-pandemic emissions intensity projections. Historical GDP data was sourced from the World Bank (World Bank, 2020a). Growth rates from the ADB report are used to project pre-COVID-19 GDP from 2020 to 2030 (ADB, 2013b).
To capture a wide range, we compare several GDP projections to account for the pandemic. The CAT compared scenarios from the IMF, the World Bank, the Asian Development Bank (ADB, 2020; IEA/IMF, 2020; World Bank, 2020b). The Government Budget provides GDP projections for fiscal years, and was not used as a direct comparison, however the GDP projections were similar to the range from the sources listed above (Ministry of Finance, 2020b). The CAT calculations are based on the largest range of scenarios available, and then choosing the maximum and minimum emissions out of all the scenarios to create a maximum and minimum range. The CAT applies the GDP growth rate of the pre-pandemic GDP projections to estimate GDP beyond the years that each scenario reported.
Global Warming Potentials
Previous assessments of the Climate Action Tracker used the global warming potentials (GWPs) from the IPCC’s Second Assessment Report (SAR). For this assessment we have updated all figures and time series to GWPs from the Fourth Assessment Report (AR4).