v3.3 1/7/97
40% speedups achieved by removing redundant calculations and general tidying. 6-region and 200-country versions made to be exactly the same shape.
v3.4 13/7/97
First web-published version. Minor bug in computation of k fixed while tidying computation algorithm. Care taken to get right bits unhidden, in right order, and focus in the right place on each sheet. How-to-use and GCI-is documents written.
v3.5 17/7/97
Added stored-scenario feature, so far to 6-region version only. Made used values into an array to prevent data entry in the wrong place.
v3.6 18/7/97
Reordered parameters to group contraction- and convergence-related ones. Minor enhancements to presentation on control sheet. Added contraction scenario feature. All scenarios now work with 200-country version
v4.0 10/7/97
Completed enhancements for Oslo conference by adding options for deferred start of convergence and linear convergence, and inserting all the preset scenarios for Oslo.
v4.1 27/7/97
Added control feature showing % Annex 1 emissions reductions by 2010.
v4.3 8/10/97
Added new line in control field to display maximum global reductions. Also experimented with Excel’s solver feature which can give you scenarios with, say 2% in this field while varying a few of the parameters. Changed a few of the scenarios to be consistent with GCI’s Oct97 ideas for Kyoto.
v5.0 16/11/97
Removed the delayed start of convergence feature, by re-adding other changes to v3.6. Changed 1990-2000 data for some countries as per UNFCCC and reports from Bonn meeting.
v5.1 14/2/98
Added formulae to work out concentrations and an extra chart sheet to display them.
v5.2 16/2/98
Added extra computations and chart to display a ‘no-absorptions’ concentrations profile.
v5.3 8/3/98
Added 22nd century, with different, much simplified, algorithms, just converging smoothly towards the desired concentrations. Needed to go for only displaying even numbered years, rather than every year, to fit into Excel.
v5.4 18/3/98
Added in formulas to compute and graphs to display temperature rises, using all 3 of the IPCC’s ‘temperature sensitivities’.
V5.5 1/1/99
Slight amendment to the temperature and concentration formulae, to be fully consistent with each other. Tidied up and improved documentation and converted it into html. Copyright notice extended and put onto separate worksheet. Posted on gci.org.uk
V7.1 1/2/03 Added feature to enable user definition of 'regions' i.e defined groupings of countries
V7.2 29/7/03 Corrected raw data by adding in latest CO2 emissions numbers from CDIAC
V7.3 27/8/03 Revised concentrations=>temperature relatiionship to be consistent with Hadley 2002 paper "Stabilisation and Commitment to Future Climate Change". Steeper temp growth. A few extra illustrative scenarios added.
V8.0 18/9/03 Basic structure transposed to permit addition of more rows to give 1-year interval instead of 2-year.
V8.1 30/09/03 Added in second temperature option reflecting carbon-cycle feedbacks. Much steeper conc & temp growth.
V8.2 25/11/03 Added in revised UN median population forecasts (1950-2050). Fixed bug in contraction scenarios feature. Many formulae simplified (to speed it up) from 2051 on as UN pop forecasts only go up to 2050. Completes conversion to interyear spacing of 1 rather than 2.
V8.3 27/11/03 Fixed bug in percap, adjusted 2200 target formula to conform to Hadley-accelerated warming. Removed flat section between contraction year and 2200. Changed em/conc formula a bit more. Extended percap calcns back to 1950.
V8.4 29/11/03 Added damages curves based on Munich re's 50s-90s damages figures. Reintroduced regional version.
V8.5 2/12/03 Adjusted formulas again. Introduced r<nnn>, BAU and t<n> scenarios. Removed exponential convergence option. Added alarm display of Xs for infeasible solutions. Uploaded to gci website.
V8.6 23/12/03 AdjCorrected minor bugs in computation of 110-year integral. Small consequential changes to new scenarios.