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https://carleton.ca

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
56
GRADE
D
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
3.86g CO2 per view
FIX
3.86g CO2 per view
Critical::
3.86g CO2 per page view
This page transfers 13.6 MB, producing an estimated 3.86g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.71g, network 0.67g, end-user device 2.48g.
Got: 3.86g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 463.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 463.1 kg of CO2 annually — equivalent to charging 57888 smartphones.

3.86g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 13.6 MB

Your site
3.86g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.71g
Network
0.67g
End-user device
2.48g
At 10,000 monthly views: Monthly: 38.6 kg · Annual: 463.1 kg · ≈ 57888 smartphone charges
D
Green Hosting
Action
Unknown
FIX
Unknown
Info::
Hosting provider could not be identified
Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their renewable energy commitments.
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 HostingUnable to Determine
Hosting Not identified✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
95th percentile
FIX
95th percentile
Warning::
3.86g 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

3.86g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 543% more
vs Target 672% 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
99% cached
PASS
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 140 KB (vs 13954 KB first visit). 138 of 144 resources are served from browser cache, saving 3.82g CO2 per repeat visit.
Info::
Repeat visit: 0.04g CO2 (first visit: 3.86g)
First visit
13954 KB
Repeat visit
140 KB

99% reduction on repeat visits

Saving 3.82g CO2 per returning visitor

138 resources served from cache · 6 resources re-downloaded

A+
Transfer Efficiency
95% efficient
PASS
95% efficient
Info::
Transfer efficiency: 95%
Only 633 KB of potential savings identified. Your page is well-optimized for size.
95% efficient

Total waste: 633 KB (5% of page weight)

Unused JS 633 KB

0.18g unnecessary CO2 per visit

Actual transfer 13954 KB
Theoretical minimum 13320 KB
Potential savings 633 KB (0.18g 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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