From just tracking temperature it may not be clear we are seeing climate change or weather variations. There are also cycles in the climate, like El Niño, which

From just tracking temperature it may not be clear we are seeing climate change or weather variations. There are also cycles in the climate, like El Niño, which cause temporary increases in temperature. So I do think tracking emissions, or rather actual level of CO2-equivalents, is a much more reliable indicator of 'how we are doing' on the longer term. The CO2e levels are (a) cause of temperature, so it is the latter which is derivative of the former. But mostly, emissions are what we are directly responsible for and can influence, temperature increase is just the result of that and we have no direct control over. Obviously we measure and study both and they both matter so the point is somewhat moot.