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Global climate change is the major and most urgent global environmental issue. Australia is already experiencing climate change as evidenced by higher temperatures and more frequent and severe droughts. These impacts are compounded by increasing land use pressures on natural resources and native ecosystems. This paper provides a synthesis of the interactions, feedbacks and risks of natural climate variability, climate change and land use/land cover change (LUCC) impacting on the Australian continent and how they vary regionally. We review evidence of climate change and underlying processes resulting from interactions between global warming caused by increased concentration of atmospheric greenhouse gases and modification of the land surface. The consequences of ignoring the effect of LUCC on current and future droughts in Australia could have catastrophic consequences for the nation's environment, economy and communities. We highlight the need for more integrated, long-term and adaptive policies and regional natural resource management strategies that restore the beneficial feedbacks between native vegetation cover and local-regional climate, to help ameliorate the impact of global warming. [ABSTRACT FROM AUTHOR]

Drought is projected to become more severe and widespread as global warming continues in the twenty-first century, but hydroclimatic changes and their drivers are not well examined in the latest projections from phase 6 of the Coupled Model Intercomparison Project (CMIP6). Here, precipitation (P), evapotranspiration (E), soil moisture (SM), and runoff (R) from 25 CMIP6 models, together with self-calibrated Palmer drought severity index with Penman–Monteith potential evapotranspiration (scPDSIpm), are analyzed to quantify hydroclimatic and drought changes in the twenty-first century and the underlying causes. Results confirm consistent drying in these hydroclimatic metrics across most of the Americas (including the Amazon), Europe and the Mediterranean region, southern Africa, and Australia, although the drying magnitude differs, with the drying being more severe and widespread in surface SM than in total SM. Global drought frequency based on surface SM and scPDSIpm increases by ∼25%–100% (50%–200%) under the SSP2-4.5 (SSP5-8.5) scenario in the twenty-first century together with large increases in drought duration and areas, which result from a decrease in the mean and flattening of the probability distribution functions of SM and scPDSIpm, while the R-based drought changes are relatively small. Changes in both P and E contribute to the SM change, whereas scPDSIpm decreases result from ubiquitous PET increases and P decreases over subtropical areas. The R changes are determined primarily by P changes, while the PET change explains most of the E increase. Intermodel spreads in surface SM and R changes are large, leading to large uncertainties in the drought projections. SIGNIFICANCE STATEMENT: Drought may become more severe and widespread under greenhouse gas (GHG)-induced global warming in the twenty-first century based on model projections. However, there are still large uncertainties in projected future drought changes, especially regarding the extent to which drought changes depend on drought indices and the future emissions scenarios analyzed. The latest projections from CMIP6 models reaffirm the widespread drying and increases in agricultural drought by up to 200% over most of the Americas (including the Amazon), Europe and the Mediterranean region, southern Africa, Southeast Asia, and Australia under moderate-to-high emissions scenarios in the twenty-first century, despite large uncertainties in individual projections partly due to internal variability. Ubiquitous increases in atmospheric demand for moisture under rising temperatures and precipitation decreases over many subtropical regions are the main driver of the projected drying and drought increases. [ABSTRACT FROM AUTHOR]

Mackey, R., 2007. Rhodes Fairbridge and the idea that the solar system regulates the Earth's climate. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 955 – 968. Gold Coast, Australia, ISSN 0749.0208 Rhodes Fairbridge died on 8th November, 2006. He was one of Australia's most accomplished scientists and has a special connection with Australia. In July, 1912 his father Kingsley established Fairbridge Village near Perth. It contains a chapel of elegant simplicity designed by one of the world's most famous architects of the time, Sir Herbert Baker, as a labour of love to commemorate Kingsley. Rhodes is one of the few scientists to research the sun/climate relationship in terms of the totality of the sun's impact on the earth (i.e. gravity, the electromagnetic force and output and their interaction). When the totality of the sun's impact is considered, having regard to the relevant research published over the last two decades, the influence of solar variability on the earth's climate is very strongly non-linear and stochastic. Rhodes also researched the idea that the planets might have a role in producing the sun's variable activity. If they do and if the sun's variable activity regulates climate, then ultimately the planets may regulate it. Recent research about the sun/climate relationship and the solar inertial motion (sim) hypothesis shows a large body of circumstantial evidence and several working hypotheses but no satisfactory account of a physical sim process. In 2007 Ulysses will send information about the solar poles. This could be decisive regarding the predictions about emergent Sunspot Cycle No 24, including the sim hypothesis. According to the sim hypothesis, this cycle should be like Sunspot Cycle No 14, and be followed by two that will create a brief ice age. During the 1920s and '30s Australia's Bureau of Meteorology published research about the sun/climate relationship, especially Sunspot Cycle No 14, showing that it probably caused the worst drought then on record. [ABSTRACT FROM AUTHOR]