Climate and Energy Action Plan (CEAP)

CLIMATE TRENDS & PRO JECTIONS | CITY OF ASHLAND, OREGON | FINAL REPORT | 31 Figure 23. The green band shows how global average temperature would have changed over the last century due to natural forces alone, as simulated by climate models. The blue band shows model simulations of the effects of human and natural forces (including solar and volcanic activity) combined. The black line shows the actual observed global average temperatures (Walsh et al., 2014b) . How do scientists project future climate change? Climate scientists use global climate models to make projections of how temperature, precipitation, and other climate indicators may change in the future . These models use mathematical and physical equations to represent the fundamental laws of nature and relevant climate processes (see Figure 24). They reproduce well the global features of the current climate and the significant warming trend over the last half -century. Hence, climate models are useful tools for exploring how climate may change in the future in response to increa sing heat -trapping gases and other external forcings .