Comparison of Climate Downscaling Methodologies

1. Study 1: Climate change effects on pasture systems in South Eastern Australia

Among 3 methodologies of downscaling, Collen and others authors could use the change factor. Collen et al (2009) mentioned in the paper, there were 5 areas in Eastern Australia which was simulated the impact of climate change on the pastoral systems. They considered the observation data of 30 years from 1971- 2000 as baseline and 3 climate simulations in the future to identify impacts of changing in climate. Despite normal baseline from 1961 – 1990 was usually applied, the nearer period was adopted to present recent climate information. In addition, the scenarios of greenhouse emission in 2030 and 2070 were used to analyzing the climate change effects. According to Harris et al (2014), the combination between the historical data and future scenario to adjust and analyze information proved that Cullen and other authors could use the change factors method.

Advantages

- Observation data were collected in near period which can present more accuracy

- This method did not need some technical knowledge compared to dynamical downscaling or statistical downscaling.

Disadvantage

- Cullen et all (2009) emphasized that the method only presented climate changes but it did not integrate other projections such as high rainfall or heat waves.

- The model also did not discover any new climate change information.

2. Study 2: Resistance of pasture production to projected climate changes in South Eastern Australia.

Similar to the research in 2009, Cullen et al (2012) applied the change factor method to study the response and adaptation of pasture production to climate change in the region of South Eastern Australia. The authors used some models combining with observation data to draw the climate change influences on pasture annually. They collected the historical climate data in the period of 1971 – 2000 as a baseline. In addition, Sustainable Grazing Systems Pasture model and others were run.

Advantages:

- Harris et al (2014) pointed out that the change factor was a simple and easy method, therefore this method suitable for the research which enabled for non-technical readers to approach the climate change effects (Cullen 2012).

Disadvantages:

- Cullen et all (2012) emphasized that the method did not integrate other projections such as drought and heat waves which may influent on the stability of some pasture types.

- The model also did not discover any new climate change information.

3. Study 3: Climate change and broad acre livestock