Local

• Global Warming
  caused by greenhouse gas emissions
  i.e. $gCO_2eq$

• Pollution

• Bio Hazard

Cover

Aside

Forecast

One Life
or even YOLO

Budget

Carbon Footprint

• Data Rate: \(213 \frac{TB}{h}\)

• Carbon Rate: \(\frac{4.2tCO2eq}{h}\)

• Budget Rate: \(\frac{2.1\,\mathrm{cap.} \cdot \mathrm{yr} }{h}\)

• Population: \(18.4\,k \mathrm{cap.}\)
  or Dudweiler

User

• Search less ^Reduce
  in the old days, people discussed about facts for an hour

• Search differently ^Rethink
  e.g. using ecosia.org; smaller footprint

Provider

• Lose weight ^Reduce
  lower data volume per visit

• Host green ^Reduce
  lower carbon per data volume

Minification

Compression

Message Formats

Lossless

• Smaller,
  with restorable original.
  Usually code.

  Deduplicate byte patterns, outside language.
  Explicit decompression step needed.

Lossy

• Smaller,
  not restorable.
  Usually media.

• Merge information content, aim for minimal perceivable effect.
  Format stays.

JSON (157B)

{
  "messages": [
    { "user": "A", "message": "Hello World!", 
	  "timestamp": "2022-02-22T22:22:22Z"},
    { "user": "B", "message": "Hi there!",
	  "timestamp": "2022-02-22T22:22:22Z"}
  ]
}
							

								81 a8 6d 65 73 73 61 67 65 73 92 83 a4 75 73 65 72 a1 41 a7 6d 65 73 73 61 67
								65 ac 48 65 6c 6c 6f 20 57 6f 72 6c 64 21 a9 74 69 6d 65 73 74 61 6d 70 b4 32
								30 32 32 2d 30 32 2d 32 32 54 32 32 3a 32 32 3a 32 32 5a 83 a4 75 73 65 72 a1
								42 a7 6d 65 73 73 61 67 65 a9 48 69 20 74 68 65 72 65 21 a9 74 69 6d 65 73 74
								61 6d 70 b4 32 30 32 32 2d 30 32 2d 32 32 54 32 32 3a 32 32 3a 32 32 5a
								

Caching

(HTTPS)
Server Push

Lazy Loading

Heuristic

• Server responds with
  some.file including
  Date and LastModified.

• Client stores response for processing.

• If enabled, cache response for 10% of timestamp difference.

• Accessing some.file before: use cache.

Explicit

HTTP/1.1 200 OK
Content-Type: text/html
Content-Length: 1024
Date: Tue, 22 Feb 2022 22:22:22 GMT
Cache-Control: max-age=604800
…
							

• Relative: max-age

• Absolute: Expires

with Push

Server knows that
 index and  fancy
go together.
Tells the client on request.

server {
    listen 443 ssl http2;

    location = / {
        http2_push /img/fancy.png;
        root /var/www/html;
        index index.html;
    }
}
							

Local Intensity

• Differs between places.
  Got solar panels? Wind mills?

• Differs along "circuits".
  data center, switches, (fibre) cables, home router, smart phone

Ideas

• Pick a green residential energy provider.

• Pick a hosting provider that does.
  there are online sources

Idea

• On load: access extra resource.

• Extra resource is behind CDN.
  Content Delivery Network: geo-distributed replicas

• Estimate location L via replica.

• Ask ElectricityMaps for I(L).

• Return I to adaptive client.

in Action