In assessing the impact of global tourism on climate change, emissions from transport receive the most attention although emissions associated with accommodation account for more than 20% of the total. A plethora of hotel certification schemes have been established worldwide that assess various environmental performance indicators, among them energy use. However, none explicitly quantify CO2 emissions, and in many, energy is poorly accounted for, or other non-energy related factors are weighted so that the overall impact of energy use (and hence CO2 emission) is weak. The main thrust of the research is to ascertain the effect of certification on CO2 emissions. The research questions whether the certification schemes are robust and rigorous and whether the results are credible. First, four widely used certification schemes are compared Nordic Swan (Scandinavia), Green Globe (Worldwide), EU Flower (European) and Green Hospitality Award (Ireland). The key issues are identified such as performance and process related criteria, use of benchmarks, and the weighting of different categories. A comparison is made with LEED-EB, a well-established environmental certification scheme, not dedicated to the hotel sector. Secondly, the way in which emissions from electricity, including so-called green electricity and carbon offsetting, are accounted for is examined since it is found that in obtaining certification, this often plays an important part. Actual annual energy use data is desperately needed as feedback to designers, managers and owners in order to give confidence that certification schemes have true validity. Results are presented from large multi-hotel data samples and for detailed results from the quality, illustrative in-depth studies which provided invaluable insight into the technical realities of a multitude of causes and effects which can often be masked in large data samples. An analysis was carried out for four In-depth studies located in Sweden (Nordic Swan), Maldives (Green Globe), Malta (EU Flower) and Ireland (Green Hospitality Award). Global CO2 emissions were compared and calculated from the delivered electricity and fuels consumption data from seventy selected certified hotels worldwide. No corrections were made in the calculations for climate, quality of services, existence of services etc. The performance indicator used is kgCO2 per guest night.

The analyses shows no clear pattern. CO2 emissions show a wide variance in performance for 8 hotels certified under different schemes, as well as for 28 hotels certified under the same scheme. In some cases emissions reduced after certification in others no change. Certified hotels do not necessarily have lower emissions than uncertified hotels and a comparison of before – and after – certification shows no significant improvement prior to certification. Most dramatically emissions from certified hotels widely vary by a factor of 7. Although it is arguable a number of corrections should be made to account for different climates, the research highlights that hotels with high CO2 emissions are being awarded certification and it questions what message‘certification’ gives to guests and other stakeholders. At worst it appears ‘business as usual’ can achieve certification with no obvious improvement in performance.
The overall conclusion is that existing certification schemes do not properly account for CO2 emissions and do not produce more energy efficient (or less CO2 intensive) buildings. Hotel accommodation was found to be more CO2 intensive than domestic emissions. The findings also uncovered inconsistencies in current methods of certification and indicate a vital need for improved methods. The results also challenge prevailing aesthetic stereotypes of sustainable hotels. The author concludes a simple CO2 accounting method is needed as the first step of a diagnostic process leading to a solution i.e. reduced emissions, to the problem i.e. high energy consumption and/or emissions, thus reducing the environmental impact (in terms of emissions reduction) of the hotel. This method of accounting can be adopted universally by using a Regional, European (O.475 kgCO2/kWh) or Universal (0.55 kgCO2/kWh) conversion factor. In relation to the proper calculation of energy and CO2 emission, sub-metering is a key factor, and with current technological developments, realistic and affordable. Furthermore, apart from certification itself, an essential quality with any monitoring system is that the user can obtain results easily and understandably, in order to get feedback from their actions. This could be facilitated by incorporating sub-metering as part of the building environmental management system software. This ensures that the certification activity is not simply a benchmark, but is also part of a diagnostic and educational process, which will continue to drive emissions down. Only then should it be ethically justified to use as a marketing tool providing diagnostic support in existing buildings, and design and operational guidance for new designs.