www.un.org

The numbers

First visit

0.771 g CO₂e

Return visit

<0.001 g CO₂e

Hosting

unknown

LCP

1.01 s

CLS

0.406

TTFB

11 ms

At 10,000 views a month this page emits about 69.4 kg CO₂e a year, roughly 284 km in an average petrol car. The estimate assumes 75% new and 25% returning visitors, a measured cache reload ratio of 0%, and world-average grid intensity. How we calculate this

1. Defer video and audiosave ~0.328 g/visit (2.95 MB)High impact · quick fix

   3.69 MB of audio/video downloads during initial page load; 1 video autoplays.

   Never autoload media: use preload="none" with a poster image, load players on interaction, and stream in an efficient codec (AV1/HEVC).

   • UNFLAG.mp43.69 MB

   WSG 2.9: Optimize media to reduce resource use
2. Convert and compress imagessave ~0.058 g/visit (518 kB)High impact · quick fix

   4 images (1.15 MB) ship in legacy formats (JPEG/PNG/GIF).

   Serve AVIF (or WebP) with responsive srcset sizes, and re-compress oversized files. AVIF typically halves JPEG weight at the same visual quality.

   • Flag.jpg1.14 MB
   • un-logo.png9.3 kB
   • copyright.png2.4 kB
   • questionmark.png1.0 kB

   WSG 2.9: Optimize media to reduce resource use
3. Audit third-party servicessave ~0.018 g/visit (158 kB)Medium impact · moderate effort

   8 third-party domains account for 316 kB (6% of the page).

   Remove services that no longer earn their place; load the rest on interaction (facades for embeds, delayed consent-gated tags). Each third party is also a privacy and performance dependency.

   • www.googletagmanager.com168 kB
   • fonts.gstatic.com67 kB
   • code.jquery.com31 kB
   • www.google-analytics.com22 kB
   • ssl.google-analytics.com18 kB
   • maxcdn.bootstrapcdn.com7.2 kB

   WSG 3.5: Treat third parties the same as first parties
4. Reduce JavaScript payloadsave ~0.0067 g/visit (60 kB)Medium impact · moderate effort

   5 scripts total 240 kB on the wire (683 kB decoded). Bundles this size usually carry a lot of unused code.

   Split bundles per route, tree-shake dependencies, and audit with a bundle analyzer or coverage profile. A 25% cut is a conservative target for bundles this size.

   • js168 kB
   • jquery-3.7.1.min.js31 kB
   • analytics.js21 kB
   • ga.js18 kB
   • splash.js2.0 kB

   WSG 3.2: Minify and remove unused codeWSG 3.3: Modularize bandwidth-heavy components
5. Verify your hosting energyMedium impact · moderate effort

   This host has not published renewable energy evidence with the Green Web Foundation, so its energy source is unknown.

   Choose a provider listed in the Green Web Directory, or ask your current provider to publish evidence (and a carbon.txt). This cuts the data-center share of every single page view.

   • carbon.txtNo carbon.txt found at the site root; publishing one is the lightest first step.

   WSG 4.1: Use sustainable hosting
6. Upgrade compression beyond gzipsave ~0.0019 g/visit (17 kB)Advisory · quick fix

   112 kB of text ships gzip-compressed; Brotli or Zstandard would cut roughly another 15-20%, and browsers without them fall back to gzip automatically.

   Serve precompressed Brotli for static text assets (highest level, compressed at build time) and enable Brotli or zstd for dynamic responses; keep gzip only as the fallback.

   • jquery-3.7.1.min.js31 kB
   • analytics.js21 kB
   • bootstrap.min.css20 kB
   • ga.js18 kB
   • animate.css5.2 kB

   WSG 4.3: Reduce data transfer with compression
7. Remove references to broken resourcessave ~<0.001 g/visit (210 B)Advisory · quick fix

   1 request answered 4xx/5xx on load: transfer and connections spent on nothing, on every single visit.

   Delete or fix the references (stale asset URLs, dead third-party tags). Each one is a request the page provably does not need.

   • white-stripe.jpgHTTP 404 · 210 B

   WSG 4.4: Setup necessary error pages and redirection links
8. Set a page-weight budgetAdvisory · moderate effort

   At 5.20 MB per view this page rates F. The findings above list where the weight is.

   Agree a transfer budget (e.g. under 975 kB reaches a B), enforce it in CI, and re-scan after each change to hold the line.

   WSG 3.1: Set goals based on performance and energy impact
9. Remove the entry redirectAdvisory · quick fix

   The address that was scanned goes through 1 redirect before the document is served, ending at https://www.un.org/. Every hop is a full round trip on a connection that has not warmed up yet.

   Point links, sitemaps and canonical tags at the final address, and make the host redirect in one hop rather than chaining http to https to www.

   • https://un.org/redirects to https://www.un.org/

   WSG 4.4: Setup necessary error pages and redirection links

Where the bytes are

• Audio / video3.69 MB · 1 req
• Images1.15 MB · 5 req
• JavaScript240 kB · 5 req
• Fonts67 kB · 2 req
• CSS43 kB · 8 req
• HTML3.8 kB · 1 req
• Data (XHR)462 B · 1 req
• Data (fetch)0 B · 1 req