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https://northwestern.edu

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
54
GRADE
F
FIX
3
REVIEW
1
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 1 REVIEW 3 FIX
F
CO2 Per Page Load
Action
3.44g CO2 per view
FIX
3.44g CO2 per view
Critical::
3.44g CO2 per page view
This page transfers 12.1 MB, producing an estimated 3.44g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.64g, network 0.59g, end-user device 2.21g.
Got: 3.44g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 412.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 412.6 kg of CO2 annually — equivalent to charging 51571 smartphones.

3.44g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 12.1 MB

Your site
3.44g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.64g
Network
0.59g
End-user device
2.21g
At 10,000 monthly views: Monthly: 34.4 kg · Annual: 412.6 kg · ≈ 51571 smartphone charges
D
Green Hosting
Action
Not green
FIX
Not green
Info::
No confirmed renewable energy commitment detected
Consider providers like Cloudflare, Google Cloud, or Vercel that match 100% of their energy use with renewables.
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 HostingNot Green Hosted
Hosting Apache HTTP Server✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
95th percentile
FIX
95th percentile
Warning::
3.44g CO2 — above the median website (0.60g)
Heavier than an estimated 5% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 95th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

3.44g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 473% more
vs Target 588% more
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Repeat Visit Weight
100% cached
PASS
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 12 KB (vs 12431 KB first visit). 104 of 105 resources are served from browser cache, saving 3.43g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 3.44g)
First visit
12431 KB
Repeat visit
12 KB

100% reduction on repeat visits

Saving 3.43g CO2 per returning visitor

104 resources served from cache · 1 resources re-downloaded

A+
Transfer Efficiency
99% efficient
PASS
99% efficient
Info::
Transfer efficiency: 99%
Only 168 KB of potential savings identified. Your page is well-optimized for size.
99% efficient

Total waste: 168 KB (1% of page weight)

Unused JS 168 KB

0.05g unnecessary CO2 per visit

Actual transfer 12431 KB
Theoretical minimum 12262 KB
Potential savings 168 KB (0.05g CO2)

See Deep Analysis sections above for specific optimizations.

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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