Progress in these areas may be relatively easy to measure (e.g. levelised cost of electricity for different technologies as in UNEP, 2013), but will be difficult to attribute to specific interventions or policies owing to time-lag issues, uncertainty and difficulties in determining causality over time. By annualising the needs for longer-term impacts, this type of analysis overcomes the time lag that complicates evaluating the effectiveness of today’s interventions in achieving future global climate goals. However, certain types of mitigation interventions such as technical assistance, capacity building, or policy and regulatory reforms will still be difficult to relate to impacts.