3 ms·
What happened with methane in 1995?
by drdrey 3y ago
What happened with methane in 1995?
- evandijk70 3y agoI have no idea, but it may be related to 'mad cow disease', which peaked around that time.
- magneticnorth 3y agoWhat are you seeing in 1995? The methane charts I'm looking at don't have anything that stands out to me then. I'd be curious to know why we had a downward trend in methane from mid-80s to mid-oughts, and what caused that reverse over the last 20 years.
- wenebego 3y agoIirc its a combination of lowered emissions, as well as the sun breaking down methane in the atmosphere
- marcosdumay 3y agoKeep in mind that "amount of methane in the atmosphere" is already something that depends on a slowly moving average of our emissions rate (first derivative of emissions). So its rate of change is a second derivative, and is supposed to look noisy unless we are doing something very wrong. My interpretation from that graph is that we were doing something very wrong until some point around the 70's. Then we just improved a bit. Also, that breakdown by source isn't reliable at all. We only started to really measure it by the 2020's.
- graeber_28927 3y agoThis is an interesting way of describing it! Can you explain why the amount of methane follows the first derivative of the amount of emissions? I understand the math, but I guess I don't know how chemistry leads to that.
- marcosdumay 3y agoMethane decomposes on the atmosphere (it burns into CO2 and H2O). It has a ~20 years half-life.
- abeppu 3y agoI'm more curious about methane in 2004, where the chart seems to show a _negative_ yoy change, and N2O in 1987? The detail page on the N2O graph says that measurements are better from the late 1990s forward, but they don't show error bars anywhere. The detail page for the methane graph mentions Pinatubo, but that was more than a decade before the low point.
- chrisfosterelli 3y agoWe started measuring global methane in the 1970-1980s. We know the rate of increase fluctuates a lot and don't fully understand all of the causes going into it on the short term scale. The data before then is based on gas bubble samples trapped in ice and is smoothed as a result.