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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
3.85g CO2 per view
FIX
3.85g CO2 per view
Critical::
3.85g CO2 per page view
This page transfers 13.6 MB, producing an estimated 3.85g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.71g, network 0.67g, end-user device 2.47g.
Got: 3.85g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 461.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 461.9 kg of CO2 annually — equivalent to charging 57733 smartphones.

3.85g

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
3.85g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.71g
Network
0.67g
End-user device
2.47g
At 10,000 monthly views: Monthly: 38.5 kg · Annual: 461.9 kg · ≈ 57733 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::
3.85g 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

3.85g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 541% more
vs Target 670% 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 13917 KB first visit). 137 of 143 resources are served from browser cache, saving 3.81g CO2 per repeat visit.
Info::
Repeat visit: 0.04g CO2 (first visit: 3.85g)
First visit
13917 KB
Repeat visit
140 KB

99% reduction on repeat visits

Saving 3.81g CO2 per returning visitor

137 resources served from cache · 6 resources re-downloaded

A+
Transfer Efficiency
95% efficient
PASS
95% efficient
Info::
Transfer efficiency: 95%
Only 632 KB of potential savings identified. Your page is well-optimized for size.
95% efficient

Total waste: 632 KB (5% of page weight)

Unused JS 632 KB

0.17g unnecessary CO2 per visit

Actual transfer 13917 KB
Theoretical minimum 13284 KB
Potential savings 632 KB (0.17g 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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