Ben Matthews

  • New here on lemmy, will add more info later …
  • Also on mdon: @benjhm@scicomm.xyz
  • Try my interactive climate / futures model: SWIM
  • 0 Posts
  • 287 Comments
Joined 1 year ago
cake
Cake day: September 15th, 2023

help-circle
  • Back in 2011, I with my young family took a local bus north from Mariana, which diverted through several villages including that one Bento Rodrigues just below the dam, soon to be washed away. Through gaps in the trees we could glimpse those huge orange lakes just behind earth dams - it was obvious even to a casual tourist that it was a disaster waiting to happen. But the bus was run by the mining company, like all services around there, I suppose that’s why people didn’t complain more.
    By the way I was told Brazil didn’t even make much from iron mines, as most of raw ore was exported to China, which got the real value.


  • Emissions grew in 2023, that’s not the same as ‘are now growing’. There is a good chance global CO2 emissions fall in 2024, mainly due to trends in China. Of course it takes time to gather data, but NS should be more careful with the headline.
    The spinscore link has useful refs - but keeps mixing up CO2 emissions with “CO2 equivalents” including methane, landuse and minor gases. Methane rising is a big issue, but might potentially be turned around faster. Regarding landuse, deforestation was exacerbated last year by El Niño feedbacks - it’s hard to separate the anthropogenic part of these fluxes.
    Rather than simple headlines which encourage fatalistic doom, it’s more useful to explain how some factors progress better than others. They are right to highlight growth in road transport and aviation (even if some growth still covid-rebound), although more effort still needed in all sectors.


  • Sure, China needs more ambitious medium-term climate targets, and this matters as its emissions are such a large fraction of the total, so their projections strongly influence global climate goals. But much changed recently - their capacity for renewables is huge, and road transport electrifies. Meanwhile China is heading downhill now - population is clearly declining, emissions probably are too (awaiting latest data), and maybe even economy depending on which statistics you believe, and whether there’s any soft-landing from the housing stall.
    So the peaking target is probably no longer relevant, although they may still have trouble with their gdp intensity targets (due lower gdp than expected) - but there are various ways to re-interpret that.
    It doesn’t surprise me that Tsinghua profs try to keep options open to nourish the dreams of the old men in power - just maybe their three-child policy will bear fruit, maybe people want even more highways and bridges to nowhere, or they can keep exporting such projects (including their steel) to africa, south asia etc.
    China also occasional gets extra-cold blasts some winters, which may help to explain keeping coal power capacity as a backup, while also keeping regional coal tycoons on-side, but on average this capacity may not get used much.
    So when comparing targets, and especially aggregating such targets across countries to project the climate outcome, it’s important to bear in mind that the gap between official ambition and reality - the probability of meeting emissions targets - differs a lot between countries, this partly reflects political systems - and China seems particularly ‘conservative’ in this regard …


  • Looking forward - eventually - to trying out the wasm option, which might eventually help speed up my interactive climate-scenario model which already runs with scala.js. Although speed is not currently the limiting factor, a wasm option might expand the potential scope - for example to increase regional resolution. However I presume to do this I’d have to refactor the code a lot, to keep all the gui and io in js while pushing the intensive calculations to wasm, and create data interfaces between these (at a rather low level if i understand correctly?), which could get tricky as it’s tightly coupled, code evolved over 24 years …
    Puzzled why wasm is promoted for “backend”, which already has other compilation targets (jvm, native), seems to me this is a bigger opportunity to do complex calculations in the browser.












  • Regarding the map - an annual average cost is not so meaningful - in higher latitudes solar is not enough in winter - especially where it’s mostly cloudy during the first half of winter. Wind helps the balance but not everywhere, always. Of course, the sophisticated models behind the article know all that, the issue is simplistic presentation. I note “we assume hydrogen is used for seasonal storage” - this may be rather optimistic - how many dark months can that cover?