**5. Concluding remarks**

Climate change disturbs a number of variables that determine how much plants can grow and develop. Extreme temperatures, elevated CO<sup>2</sup> together with a decrease in water availability and changes to soil conditions will essentially make it more challenging for plants to thrive. Overall, climate change is expected to decline the growth and development of plants, particularly with reference to agricultural systems. Declining plant growth also dramatically changes the habitats that are necessary for many species to survive. Undoubtedly, under the current threat of climate change, it is urgent to address the molecular and biochemical mechanisms that underlie plant responses to several abiotic stresses and combinations thereof. However, a complete understanding of plant responses to climate change is best obtained if data is integrated at several levels, including morpho-physiological and developmental studies as well as molecular studies that comprise the so-called *omics* technologies. Up to now, metabolomics studies have already provided a promising basis for facilitating our understanding of the plant's flexibility to reconfigure central metabolic pathways (i.e., carbon, nitrogen and energy metabolism) as well as the degree by which plants tolerate and/or are susceptible to a climate change scenario. Nevertheless, more research efforts are crucial for a more comprehensive analysis of the impact of combined stresses in plants. Researchers must regard simultaneous multiple climate change factors, which sum will play a key negative influence on global agriculture, as a new state of stress in which the exposed plant might require differential responses from those induced by a stress alone. Further research in this area is therefore critical.
