4^th World Conference on Climate Change October 19-21, 2017 Rome, Italy

Many lines of scientific evidence show the Earth's climate is changing. This page presents the latest information from several independent measures of observed climate change that illustrate an overwhelmingly compelling story of a planet that is undergoing global warming. Our world is getting warmer. Over the last 100 years the average global surface temperature has risen by about 0.74C. For scientists studying the impacts of climate change, such questions - and answers - are constantly being revised and refined as more information is gathered, models are fine-tuned, and feedbacks are better understood.

Most climate scientists agree the main cause of the current global warming trend is human expansion of the "greenhouse effect"1 — warming those results when the atmosphere traps heat radiating from Earth toward space. Human activities are changing the natural greenhouse. Over the last century the burning of fossil fuels like coal and oil has increased the concentration of atmospheric carbon dioxide (CO2). Global warming is primarily a problem of too much carbon dioxide (CO2) in the atmosphere—which acts as a blanket, trapping heat and warming the planet.

Scenarios of changes in biodiversity for the year 2100 can now be developed, based on scenarios of changes in atmospheric CO2, climate, vegetation, and land use and the known sensitivity of biodiversity to these changes in terrestrial and freshwater ecosystems. This synthesis focuses on estimates of biodiversity change as projected for the 21st century by models or extrapolations based on experiments and observed trends. The term “biodiversity” is used in a broad sense as it is defined in the Convention on Biological Diversity to mean the abundance and distributions of and interactions between genotypes, species, communities, ecosystems and biomes.

The global carbon cycle operates through a variety of response and feedback mechanism, responses of the carbon cycle to changing CO₂ concentrations. Anthropogenic CO₂ by the ocean is primarily governed by ocean circulation and carbonate chemistry. Changes in marine biology brought about by changes in calcification at low pH could increase the clean uptake of CO₂ by a few percentage points.

Carbon dioxide (CO2) capture and sequestration (CCS) is a set of technologies that can greatly reduce CO2 emissions from new and existing coal- and gas-fired power plants and large industrial sources. Carbon dioxide (CO2) capture and sequestration (CCS) could play an important role in reducing greenhouse gas emissions, while enabling low-carbon electricity generation from power plants. Carbon dioxide (CO2) capture and sequestration (CCS) can significantly reduce emissions from large stationary sources of CO2, which include coal- and natural-gas-fired power plants, as well as certain industry types such as ethanol and natural gas processing plants.

Climate and climate-related hazards such as floods, storms, and droughts have served as trigger events for more than 75% of the disasters that have occurred globally over the past decade. Proportionately, these disasters affect the least developed countries most intensely, proving to be especially harmful to poverty stricken populations.

Climate change is expected to hit developing countries the hardest. Its effects—higher temperatures, changes in precipitation patterns, rising sea levels, and more frequent weather-related disasters—pose risks for agriculture, food, and water supplies. At stake are recent gains in the fight against poverty, hunger and disease, and the lives and livelihoods of billions of people in developing countries. Addressing climate change requires unprecedented global cooperation across borders. Historical societal adaptations to climate fluctuations may provide insights on potential responses of modern societies to future climate change that has a bearing on water resources, food production and management of natural systems. The average air temperature will increase as the earth becomes hotter. This will cause shifts in normal weather and rainfall patterns. For example, some areas may become drier, while others may become wetter. The average temperature of the sea surface will increase, which may cause coral bleaching and changes in fish distribution. Sea level will rise in many locations due to a combination of the melting of land ice in Antarctica and other areas and the expansion of ocean waters as they warm. As the level of the sea rises, this may impact the coastline and increase the intensity of storm surges. Weather patterns including storms, drought, rainy seasons, and dry seasons will change in different ways in different places and may result in more extreme events.

These shorter- term variations are mostly due to natural causes, and do not contradict our fundamental understanding that the long-term warming trend is primarily due to human-induced changes in the atmosphericlevels of CO2 and other greenhouse gases. Emerging economy nations are actively seeking to identify opportunities and related financial, technical, and policy requirements to move toward a low carbon growth path. Extreme climate events such as aridity, drought, flood, cyclone and stormy rainfall are expected to leave an impact on human society. They are also expected to generate widespread response to adapt and mitigate the sufferings associated with these extremes. Societal and cultural responses to prolonged drought include population dislocation, cultural separation, habitation abandonment, and societal collapse. A typical response to local aridity is the human migration to safer and productive areas.

Activities that aim at raising awareness and improving access to scientific information on adaptation, so that decision-makers can better integrate climate change issues in development planning and poverty reductionmeasures. The activities include national science-policy dialogues, regional knowledge sharing strategies, and regional trainings. The science-policy dialogues are designed to address the need for better two-way interaction and communication at the science-policy interface on climate change issues, particularly on adaptation. Energy efficiency opportunities, which are of particular importance to cities, are buildings and district energy systems. To build a regulatory strategy, establish enabling legislation and regulatory standards, and set up enforcement mechanisms.

Climate change is one of the defining challenges of the 21st century, along with global population, poverty alleviation, environmental degradation and global security. The problem is that ‘climate change’ is no longer just a scientific concern, but encompasses economics, sociology, geopolitics, national and local politics, law, and health just to name a few. But with so many other problems in the world should we care about climate change? What we are finding is that if we do not produce win-win solutions then climate change will make all our other problems worse.

Climate change raises significant social, environmental and legal challenges. The governance system applying to climate change is complex and multi-level. A central issue in international law and policy is how countries of the world should allocate the burden of addressing global climate change. Countries around the world are taking important domestic actions to help tackle the issue of climate change.

Climate Changes in ocean systems generally occur over much longer time periods than in the atmosphere, where storms can form and dissipate in a single day. Interactions between the oceans and atmosphere occur slowly over many months to years, and so does the movement of water within the oceans, including the mixing of deep and shallow waters. Thus, trends can persist for decades, centuries, or longer. For this reason, even if greenhouse gas emissions were stabilized tomorrow, it would take many more years—decades to centuries—for the oceans to adjust to changes in the atmosphere and the climate that have already occurred.

Sustainability broadly means balancing economic, social and environmental systems so that one ‘system’ does not adversely impact the other two. Long term changes in the average weather patterns/ temperature. Often used interchangeably with ‘Global Warming “or “Green House Gas Effect” phrases and is linked to manmade acceleration of the amount of CO2 produced globally. This diagram to illustrates the historical rise in greenhouse gas emissions over the centuries.

Carbon dioxide (CO2) is the primary greenhouse gas emitted through human activities. In 2013, CO2 accounted for about 82% of all U.S. greenhouse gas emissions from human activities. Carbon dioxide is naturally present in the atmosphere as part of the Earth's carbon cycle (the natural circulation of carbon among the atmosphere, oceans, soil, plants, and animals). Carbon dioxide is constantly being exchanged among the atmosphere, ocean, and land surface as it is both produced and absorbed by many microorganisms, plants, and animals. However, emissions and removal of CO2 by these natural processes tend to balance.

Energy is deposited in a range of energy sources, which can be non-renewable or renewable. Renewable sources of energy are those that can be refilled in a short period of time, as opposed to non-renewable sources of energy.The use of renewable sources of energy is less polluting, compared to that of non-renewable sources. Specifically, increased dependence on renewable sources of energy is a key element of efforts to avert climate change.Renewable sources of energy today make an irrelevantcontribution to total energy use, compared to that of non-renewable sources. A range of barriers hamper the widespread deployment of renewable energy technologies.

The immensity of global warming can be discouraging and depressing. What can one person, or even one nation, do on their own to slow and reverse climate change? The good news is that we know exactly what needs to be done to stop climate change - and the technologies we need already exist. With the right policies at national and local levels, we would be able to deploy them on a large scale.