https://nobelprize.org
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
84
GRADE
B
FIX
1
REVIEW
1
PASS
4
INFO
0
Checks
64 PASS 1 REVIEW 1 FIX
DCarbon BudgetAction52th percentileFIX
Carbon Budget
Action52th percentile
52th percentile
Warning::
0.68g CO2 — above the median website (0.60g)
Heavier than an estimated 48% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 52th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.68g
52nd percentile
Cleaner than 48% of websites
✗ Above the median website
vs Median 13% more
vs Target 35% more
BCO2 Per Page Load0.68g CO2 per viewREVIEW
CO2 Per Page Load
0.68g CO2 per view
0.68g CO2 per view
Info::
0.68g CO2 per page view
This page transfers 2.9 MB, producing an estimated 0.68g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.14g, end-user device 0.52g.
Got: 0.68g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 81.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 81.0 kg of CO2 annually — equivalent to charging 10128 smartphones.
Info::
Green hosting reduces data center emissions
0.68g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 48% of websites
Sustainable Web Design model v4 · Page size: 2.9 MB
Your site
0.68g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.14g
End-user device
0.52g
At 10,000 monthly views: Monthly: 6.8 kg · Annual: 81.0 kg · ≈ 10128 smartphone charges
A+Green HostingGreen (both)PASS
Green Hosting
Green (both)
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Cloudflare, CDN: Cloudflare
Info::
Cloudflare: Verified by the Green Web Foundation
Info::
Cloudflare: 100% renewable energy for global network since 2019
Info::
Green hosting status based on known provider commitments
Green hosting detection uses a curated database of provider renewable energy commitments. This is not a real-time verification. For authoritative checks, visit thegreenwebfoundation.org.
Green Hosting✓ Green Hosted
Hosting Cloudflare✓CDN Cloudflare✓
Cloudflare: Verified by the Green Web Foundation
Cloudflare: 100% renewable energy for global network since 2019
Based on known provider commitments. Verify at thegreenwebfoundation.org
A+Repeat Visit Weight95% cachedPASS
Repeat Visit Weight
95% cached
95% cached
Info::
95% reduction on repeat visits
Returning visitors download only 159 KB (vs 2921 KB first visit). 83 of 86 resources are served from browser cache, saving 0.64g CO2 per repeat visit.
Info::
Repeat visit: 0.04g CO2 (first visit: 0.68g)
First visit
2921 KB
Repeat visit
159 KB
95% reduction on repeat visits
Saving 0.64g CO2 per returning visitor
83 resources served from cache · 3 resources re-downloaded
A+Transfer Efficiency92% efficientPASS
Transfer Efficiency
92% efficient
92% efficient
Info::
Transfer efficiency: 92%
Only 242 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 242 KB (8% of page weight)
Unused JS 242 KB
0.06g unnecessary CO2 per visit
Actual transfer 2921 KB
Theoretical minimum 2679 KB
Potential savings 242 KB (0.06g CO2)
See Deep Analysis sections above for specific optimizations.
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
Whether the site is served from green-energy infrastructure
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.