Impact of Ecological Restoration on Ecosystem Services has termed such systems novel ecosystems (also known as ‘‘emerging’’ or ‘‘no-analog’’ systems) and has defined them as those ‘‘containing new combinations of species that arise through human action, environmental change, and the impacts of the deliberate and inadvertent introduction of species from other parts of the world’’ (Hobbs et al., 2009; Marris, 2011) Novel ecosystems are an ambiguous concept because depending on the timeframe of interest, anything could be considered novel However, the main proponents of using novel ecosystems to help guide restoration efforts suggest that the accelerated pace and breakdown of biogeographic barriers sets current novel ecosystems apart from the past in terms of the increased rate of novel environment appearance, novel species combinations, and altered ecosystem functioning (Hobbs et al., 2009) The utility of terming systems novel seems to move restoration targets away from historical states and instead argues for ecosystem service and ecosystem function restoration goals (Jackson and Hobbs, 2009) This is laudable but much of the debate on using historical reference sites has already been settled and so the introduction of this new terminology is still somewhat puzzling Novel ecosystems have arbitrary definitions and could therefore represent a range of scenarios from a severely perturbed system to one that has been completely replaced by new species Another component of the novel system framework is the hybrid ecosystem, which also has an arbitrary definition – somewhere between a novel and an historical system – and cannot be clearly distinguished from just perturbed or novel ecosystems Indeed, a large perturbation such as logging can result in a complete replacement of the previous vegetation with new, early-successional and possibly invasive grasses Is this then a novel ecosystem because it is different from the historical past and likely made up of new species combinations? Or is it merely a perturbed system in the beginning stages of recovery? Their arbitrary definitions make novel systems impossible to distinguish from just severely perturbed systems and therefore cause difficulty in identifying the extent of their existence, illustrating their impact, and using them as potential restoration targets Despite these difficulties, the existence of novel ecosystems is certainly another good argument against using historical references in restoration, but focusing our energy on ambiguously defined and difficult-to-identify ecosystems could also take away from sorely needed advancements in using ecosystem services to calculate return on restoration investments Restoration and Global Change It is important to recognize that ecosystem repair from various perturbations is happening against a backdrop of global change that has accelerated at unprecedented rates since the industrial revolution (Baines and Folland, 2007; IPCC, 2007; Maslanik et al., 2007; Belkin, 2009; Gregory et al., 2009) From sea-level rise to heightened hurricane activity, longer and more frequent droughts and floods, and acidification of the world’s oceans, ecosystems are undergoing rapid change (Allison et al., 2009; Fuăssel, 2009) This presents an interesting conundrum: How we choose restoration targets when much of the world’s ecosystem processes are in a state of flux and are likely to continue changing for the foreseeable future? This dynamic and unpredictable climate argues against the use of historical 203 baselines for restoration because they will be increasingly impossible to recreate amidst changing biophysical conditions (Harris et al., 2006) Indeed, many have suggested that restoration of processes, rather than historical conditions, will give restoration the best chances of success in a changing world (Harris et al., 2006) In a changing world, our restoration goals are likely to include ecosystems that were never before seen in historical times because we are predicted to experience climate shifts never before realized in such a short time span The interaction between ecological restoration and global change is an understudied area that will be of rapidly growing interest as we watch systems change before our eyes Climate change also presents an interesting challenge to legislation that protects critical habitat for species of concern like the Endangered Species Act Changing ecosystem processes may mean that critical habitats will shift according to species’ biophysical envelopes, and so, protected habitats will no longer be suitable for the species the protection was created for (Harris et al., 2006) Restoration may provide a critical answer to protecting these species – it may be necessary to restore habitats and create shelter for species that will need to migrate given climate change (Harris et al., 2006) Ecological Restoration and Ecosystem Services Ecosystem Restoration Potential Human population now exceeds seven billion people and this number is projected to grow to eight billion by 2050 (United Nations, 2004) As our population grows, so too our technological demands, thirst for resources, and exploitation of nature to meet our expanding needs We have fundamentally altered most ecosystem processes, leaving few areas on Earth untouched by people in some way (Kareiva and Marvier, 2011) Humans have been domesticating nature to meet our needs for centuries (Kareiva et al., 2007), but the rate of ecosystem alteration has spiked since the industrial revolution As we continue to use nature’s capital to meet our needs, we also threaten to destroy the very resources that we depend on for survival We have transformed around half of Earth’s surface area to grazing or croplands (MEA, 2005) More than 50% of the world’s forests have been lost through this extreme transformation (MEA, 2005) Although providing food for the masses is a necessary service that ecosystems provide, it is often done at the expense of other ecosystem services such as water quality and quantity regulation, climate regulation, and carbon sequestration Our insatiable thirst for resources and to control nature has driven the largest mammals on each continent to extinction or severe depletion, fundamentally altering food webs across the globe (Woodroffe, 2000; Lyons et al., 2004) No marine ecosystem on earth is untouched by people and almost half of the world’s oceans face multiple threats (Halpern et al., 2008) As such, there is substantial concern that we are leaving a legacy of extinction, biodiversity loss, and unsustainable exploitation of nature to future generations Humans are arguably better off now than in previous generations We are able to feed the masses, control predators, alter natural disturbance regimes, and build infrastructure to help