About Us


This website was initially developed by John Davis and David Sentinella. John Davis died in a helicopter crash in November 2015. The authors, and this site, have no corporate or religious sponsorship, and have no obligations or loyalties to corporations or religious organisations. Our core belief is that we should act on information gained through careful scientific observation and deduction. John was a passionate and a vitally active member of the Greens until his tragic death. David is an active member of the Greens because the Greens accept the science and the need for action, but this is not a Greens website. What we say, or have said, may, or may not, be Greens policy. We are in various other climate action groups. We are just people who see the world going down the wrong path and want to do something. We are calling for humanity to act responsibly.

We accept the findings of science: that human activity has caused our planet to warm, and that this global warming  poses a real and imminent threat to life on this planet. We believe that, by acting logically and in concert, we can overcome this threat.


John Davis

(dec. November 2015)

BSc (Tech) Chemical Engineering.  UNSW

In Retirement

  • Sold business and retired but with remnants of video business. Partnership in Yuanlai Education China with 20 staff, agency in Germany .
  • Grey nomad touring of Australia, Europe,
  • Talks on renewable energy.
  • Building this website

21 years - Classroom Video -Founder, Managing Director.

  • Produced and Exec. produced over 400 hundred videos – mostly  science and technology.  Various prizes.
  • Founded offices in UK, France, NZ, Canada, USA, China. Agency in Germany. 40 staff in Australia and overseas.
  • Sold over 1,000,000 videos to 20,000 schools and TV, over 21 years.
  • Developed a Video on Demand software (before YouTube).

8 yrs - Australian Broadcasting Corporation.  Education producer TV.

  • Represented ABC in Japan Prize: (Physics of Surfing Waves).
  • Produced “Behind the News” 2.5 yrs.
  • Produced  about 100 x 20 minute TV programs.

3 yrs - Science and Maths teacher, (Making money to make films.)

6 yrs – Expedition Films 1966-72 in partnership.

  • 5 hrs TV adventure documentaries - PNG expeditions: "People of the Warm Mud Mountains" (Winner Sydney Film Festival doco., "In seach of the World's Deepest Cave", "Watut, White Water, Gold River", "PNG Teen age Trek" , "The 2nd Ascent of Balls Pyramid". 
  • News stringer for all channels .
  • Photojournalist, photographer. Hundred or so magazine articles in partnership.
  • Author of 2 books published by Angus and Robertson: “Science as you go, in the Outdoors”, “Rope and Rucksack”.
  • Co-founded and published magazine “Rucksack”.

9 yrs - Chemist and Chemical Engineer, 1960-79 Aust and Canada, production, design, commissioning and research and development, tendering. 

  • CSR – Sydney 1960-66, Sugar refining, building materials R&D, part time university.
  • Iotech Canada Ottawa 1 year 1979 - renewable energy from biomass research director converting trees into ethanol, resins, and other products.
  • Humphreys and Glasgow – Sydney 2 years 1973 Construction and commissioning of gas plant, Tenders manager on sewage treatment, palm oil mill, design and others.
  • The Good Oil Company – 1975 Sydney, started up waste oil recycling with engineer/backer.

Community and Hobbies

  • President Sydney Rock Climbing club. 1964-6  
  • Organised first and second ascents of Balls Pyramid.
  • Started the rockclimbing grading system for scouts.
  • Rock climbing instructor for National Fitness 1967 and Outward Bound.
  • Head of NSW volunteer rock rescue. 1962-6
  • Owner builder 1974-8, part time plumber.
  • Citizens Military Forces – Commando green beret 2 yrs 1961-2
  • Venturer leader, 1961, 1985-6. 
  • Volunteer bush regenerator.
  • Hobbies: Bushwalking, woodwork, wood turning, gardening, canoeing, ski touring, boat building and sailing, helping grown up kids build their houses.
  • Playing with grandchildren 8,8, 10, and 9 yrs. (2014) Pirates, trains, movies, beach, flying foxes, tree houses, archery, sailing, bushwalks, messing about in mountain streams, etc.
  • Greens, ran for NSW seat of Davidson. NSW Greens - Climate Action Working Group.

David Sentinella

  • David Sentinells's studies include:
  • Electrical Engineering - UTS (NSWIT);
  • Biomedical Science - UTS (NSWIT); 
  • Applied Biology - Charles Sturt University (Riverina CAE);
  • Medical Electronics - Siemens UBMed In-service training – Germany;
  • A range of management and technical courses over 30 years.

Community and Politics

  • Ran as Greens Candidate for NSW Electorate of Davidson in 2015
  • Convenor of the Hornsby Ku-ring-gai Greens
  • Member of the Greens since 2007, Volunteer for the Greens since 2004,
  • Campaign Manager for Dr Jonathan King -  July and August 2010,
  • Acting President of Pittwater Community Gardens during its formation,
  • Initiated the P4 Group  “People Protecting Public Parks”,
  • Assisted with the production of Elimatta – the Aboriginal Support Group quarterly newsletter for 20 years,
  • P&C President – Bilgola Plateau Public School – 2 years,
  • Member of the Newport Resident Association - designed, built and deployed the Newport Resident Association website (Now managed by other association members),
  • Designed, built and deployed the Northern Beaches Greens Website.


  • Electronics engineer working in the field of acoustics, air quality and a range of environmental monitoring projects

Project work over the years

  • Glass Recycling,
  • Animal Behaviour Tracking Systems,
  • Network and Systems design and implementation,
  • Writing Complete Management Systems,
  • Mining and Resource Information Systems,
  • Installation and Maintenance of a wide range medical systems (CT, Digital Angiography, X-ray, Audiology, Cardiac and others).

Business and Employment

  • 3½ years Wilkinson Murray Pty Ltd and SoundScience Ltd - Rail noise measurement and mitigation, development of electronic systems, directional sound monitoring systems, website development for environmental monitoring and other engineering software systems.
  • 10 years Business Owner - Integrated Imaging Pty Ltd Electronics, IT,  and Engineering
  • 7 years Philips Electronics - Corporate IT (Some concurrently)
  • 5 years Medical Electronics - IT Systems -  Medical Applications Pty Ltd (Philips & Siemens)
  • 13 years Field Service Engineer - Medical Applications Pty Ltd (Philips & Siemens) – Medical Imaging - CT, Digital Angiography, X-Ray and other medical equipment.
  • 2 Years Engineering Manager with System One Pty Ltd - Australian Designed and Manufactured Computer Systems and Computer Software.
  • Also experience with RF Communications, Security Systems, Video and TV Systems, Print Typesetting Equipment.

Travelled extensively

  • Australia,
  • Germany (Studied - 1 year),
  • Netherlands (studied),
  • New Zealand (worked and travelled)
  • United Kingdom, France, Italy, Austria, Poland, Czech Republic, Slovakia, United States, Peru (including Iquitos), Ecuador (including Galapagos), Chile, Malaysia, Singapore (studied), Indonesia (including Bali), , and Fiji.