by Brian Tomasik
First written: 23 Feb. 2016; last update: 12 Oct. 2017

Summary

This page summarizes cost-effectiveness estimates for various ways to reduce insect suffering. The numbers are crude and could be off by a few orders of magnitude, and the sign of the intervention (whether it's net good or net bad) is not always clear either.

Intervention Rough expected insect-years of suffering prevented per US$ Is the intervention acceptable to most people? Source
Buy beef directly from Brazil ~106 no this section
Lobby to eliminate human-biting mosquitoes 106 ? yes number in this section plus number in this section; I reduced the number by a little bit because the calculation is pretty uncertain
Promote energy efficiency / nuclear fusion -6.2 * 105 to 6.6 * 105 (very unclear if good or bad, but stakes are high) yes if reducing climate change turns out to be good; no otherwise bottom of this section
Cover rainforest land 3 * 105 no this section
Donate to Against Malaria Foundation 1.4 * 104, sign is very unclear yes this piece
Campaign against use of silk 104 yes this section
Promote gravel lawns 103 yes if targeted towards people who maintain their lawns end of this section
Discourage aerobic, bug-filled composting 5 * 102 ? maybe not, but possibly yes for people whose landfills or sewage-sludge-treatment facilities do biogas capture. below
Develop a consumer device to humanely shred household bugs 102 ? yes (coming soon)

Xysticus-sp-krabbenspinneThe top cost-effectiveness numbers here are quite impressive, even relative to the short-term impacts of helping poor humans or farm animals. An insect-year of suffering is equivalent to the pain of dying for on the order of ~10 adult insects, so the numbers in the above table can be multiplied by ~10 to give "adult-insect experiences of death prevented per $".

A human has ~106 times more neurons than an small insect. Even if you only give an insect 10-6 times the moral weight of a human, 105 insect years (containing the equivalent of ~106 adult-insect deaths) would be approximately equivalent to one human death. So dividing the cost-effectiveness numbers in the above table by 105 represents the equivalent number of painful human death experiences prevented per dollar.

Sample government policies

Following are a few policies that would probably reduce invertebrate suffering. I haven't done full cost-effectiveness estimates and so can't rank them. All of these proposals might possibly be politically feasible.

Policy Why it probably benefits insects Non-insect arguments for it
Reduce water subsidies for Western US farmers. Less irrigation plausibly means less total plant growth. Alleviate water shortages in the Western US. Save taxpayer money.
Reduce fertilizer use in agriculture. Less fertilizer use would probably reduce crop yields, which would likely reduce total invertebrate populations. Fertilizers run off into water bodies. Nitrogen-based fertilizers also contribute to climate change by increasing atmospheric nitrous oxide.
Discourage fertilization and irrigation of home lawns. Less lawn grass growth would mean less food for bugs, leading to lower bug populations. Avoid wasting water, avoid pollution due to fertilizer, etc.
Prevent oligotrophic lakes and reservoirs from becoming mesotrophic More eutrophic lakes generally seem to support more zooplankton, although this topic is complex. Most people oppose eutrophication for a variety of water-quality reasons.
Reduce funding for soil and land conservation Erosion reduces land fertility and hence long-run plant growth. Protecting wetlands and grasslands preserves productive ecosystems. Cutting this funding would save the government money.
Subsidize gravel lawns See this piece. Gravel lawns save water (which is especially appealing in dry states like California) and obviate pesticides / fertilizers.
Encourage solar farms to be built over grassland Reduces plant growth where the solar panels are built Provides green electricity
Reduce or at least don't increase federally protected lands Resource extraction and economic activity in wilderness areas usually reduce plant populations. Create jobs, reduce government bureaucracy
Oppose those rewilding projects that would increase the primary productivity of land More productivity generally means more insects. Rewilding costs money.
Support garbage incineration Burning garbage prevents bugs from eating the organic matter it contains. Incineration probably reduces greenhouse-gas emissions compared with landfilling. Other environmental pros and cons are debated.

Quick-and-dirty calculation for malaria prevention

This discussion has moved to "Does the Against Malaria Foundation Reduce Invertebrate Suffering?".

Quick-and-dirty calculation for opposing composting

Most methods of aerobically composting food waste create significant amounts of bug suffering. In an upcoming piece on this website (ETA: ~Dec. 2017), I estimate that a typical single-family vermicomposting bin contains on the order of ~102 earthworms and perhaps on the order of ~105 springtails, mites, and other non-nematode invertebrate animals. 102 + 105 ≈ 105 invertebrate-years of suffering per year of composting, ignoring the fact that earthworms may count more morally than springtails and mites on account of their larger size.

Activists could potentially encourage people who compost their food to stop doing so, or at least to use a less bug-intensive composting method. Suppose someone created an anti-composting campaign. Ignoring startup costs, suppose that a ballpark estimate of the marginal cost to dissuade one person from using a bug-filled composting method for ~5 years would be $1000. (I'm just making this up.) Then this campaign would prevent on the order of 5 * 105 / 1000 = ~500 invertebrate-years per dollar.

Actually, the number should be somewhat less than this because invertebrates might still be created by alternative food-scrap disposal methods. My calculation also ignores climate-change effects and other variables that differ between standard home composting vs. alternate methods of food-waste disposal. While the signs of these impacts are very unclear, these impacts might be important (Tomasik "Invertebrate Impacts of Worm-Bin Composting vs. Methane-Producing Decomposition").

Unfortunately, there's some chance that an anti-composting campaign would backfire. Composting has a halo around it in many people's eyes, so even discussing composting might cause more people to become interested in it than to shy away from it. This is a significant concern to explore before undertaking an anti-compost campaign.

Maybe efforts to discourage composting would be most successful in places where landfills or sewage-sludge-treatment plants have methane-capture technology. Home composting just releases greenhouse gases to the air, while methane-capture systems generate human-useable energy in the process of releasing emissions.

Re_Re_Think (2016) mentions that methane-capture technology is not perfectly efficient:

Estimates range from between 0-70% efficiency, and because methane is ~30 times more potent a greenhouse gas than carbon dioxide, disposing of organic waste into even the best methane-capture landfills (anaerobic, methane producing) contributes more towards global warming than composting (aerobic, carbon dioxide producing) them would.

Of course, that analysis assumes that compost produces only CO2 emissions, not methane. Also, production of methane fuel by other means, such as fracking, is also not perfectly efficient. The relevant comparison is between (1) biogas capture vs. (2) aerobic composting + an alternate method of methane-fuel production.

EPA (2009) estimates a somewhat higher efficiency for methane capture: "It is estimated that a [landfill gas] project will capture roughly 60-90% of the methane emitted from the landfill, depending on system design and effectiveness." Wikipedia ("Landfill gas utilization") says: "On average, closed landfills have gas collection systems that capture about 84% of produced gas, compared to about 67% for open landfills." Chardoul et al. (2015), p. 1-2: "Some landfills are equipped to capture, presently, up to 80% of the gases produced. Most landfills are not equipped to capture landfill gases."