State of the Climate 2024. Update for COP29

The World Meteorological Organization (WMO) is proud to be a sponsor of the Global Climate Observing System (GCOS) and to be able to support the production of this report. WMO is a specialized agency of the United Nations and is its authoritative voice for weather, water and climate. It sponsors and implements an integrated suite of programmes which cover all aspects of climate research, observations, assessment, modelling and services. The WMO has produced a State of the Global Climate report every year since 1993 to provide an annual summary and update of key climate indicators. These reports complement the more detailed, less frequent synthesis provided by the IPCC’s Assessment Reports. Since 2016 WMO has also been reporting preliminary findings on key climate indicators to inform the UNFCCC Conference of Parties (COP) before the end of each year. In July 2024, an international workshop organized by WMO and kindly hosted by the Deutscher Wetterdienst in Germany, agreed to a more condensed format, focusing on key messages for policymakers' needs at COP. The State of the Climate Update 2024 for COP29 highlights preliminary headline climate indicators consolidating the most up-to-date datasets available at the time of writing, along with examples of extreme events and progress in climate actions. The headlines in the State of the Climate Update 2024 give cause for great concern. Greenhouse gas concentrations continue to steadily rise, driving further long-term temperature increases, highlighting the rapid changes in our climate system in the space of a single generation. We are on track for 2024 to be the hottest year on record joining 2023 as the two hottest years on record. Ocean heat content values continued an upward trend in 2023 and 2024, contributing to other changes in the climate system such as sea level rise and fueling intense storms. Antarctic and Arctic sea ice extent in 2024 have both been well below average. The record-breaking rainfall and flooding, rapidly intensifying tropical cyclones, deadly heat, relentless drought and raging wildfires that we have seen in different parts of the world this year are unfortunately our new reality and a foretaste of our future. We must continue to strive to limit warming as much as possible, recognizing that staying well below 2°C above pre-industrial levels and pursuing efforts to limit warming to 1.5°C remains critical to significantly reduce the risks and impacts of climate change. At the same time, we need to step up support for climate change adaptation through climate services and early warnings

State of the Climate 2024. Update for COP29

The World Meteorological Organization (WMO) is proud to be a sponsor of the Global Climate Observing System (GCOS) and to be able to support the production of this report. WMO is a specialized agency of the United Nations and is its authoritative voice for weather, water and climate. It sponsors and implements an integrated suite of programmes which cover all aspects of climate research, observations, assessment, modelling and services. The WMO has produced a State of the Global Climate report every year since 1993 to provide an annual summary and update of key climate indicators. These reports complement the more detailed, less frequent synthesis provided by the IPCC’s Assessment Reports. Since 2016 WMO has also been reporting preliminary findings on key climate indicators to inform the UNFCCC Conference of Parties (COP) before the end of each year. In July 2024, an international workshop organized by WMO and kindly hosted by the Deutscher Wetterdienst in Germany, agreed to a more condensed format, focusing on key messages for policymakers' needs at COP. The State of the Climate Update 2024 for COP29 highlights preliminary headline climate indicators consolidating the most up-to-date datasets available at the time of writing, along with examples of extreme events and progress in climate actions. The headlines in the State of the Climate Update 2024 give cause for great concern. Greenhouse gas concentrations continue to steadily rise, driving further long-term temperature increases, highlighting the rapid changes in our climate system in the space of a single generation. We are on track for 2024 to be the hottest year on record joining 2023 as the two hottest years on record. Ocean heat content values continued an upward trend in 2023 and 2024, contributing to other changes in the climate system such as sea level rise and fueling intense storms. Antarctic and Arctic sea ice extent in 2024 have both been well below average. The record-breaking rainfall and flooding, rapidly intensifying tropical cyclones, deadly heat, relentless drought and raging wildfires that we have seen in different parts of the world this year are unfortunately our new reality and a foretaste of our future. We must continue to strive to limit warming as much as possible, recognizing that staying well below 2°C above pre-industrial levels and pursuing efforts to limit warming to 1.5°C remains critical to significantly reduce the risks and impacts of climate change. At the same time, we need to step up support for climate change adaptation through climate services and early warnings

State of the Climate 2024. Update for COP29

The World Meteorological Organization (WMO) is proud to be a sponsor of the Global Climate Observing System (GCOS) and to be able to support the production of this report. WMO is a specialized agency of the United Nations and is its authoritative voice for weather, water and climate. It sponsors and implements an integrated suite of programmes which cover all aspects of climate research, observations, assessment, modelling and services. The WMO has produced a State of the Global Climate report every year since 1993 to provide an annual summary and update of key climate indicators. These reports complement the more detailed, less frequent synthesis provided by the IPCC’s Assessment Reports. Since 2016 WMO has also been reporting preliminary findings on key climate indicators to inform the UNFCCC Conference of Parties (COP) before the end of each year. In July 2024, an international workshop organized by WMO and kindly hosted by the Deutscher Wetterdienst in Germany, agreed to a more condensed format, focusing on key messages for policymakers' needs at COP. The State of the Climate Update 2024 for COP29 highlights preliminary headline climate indicators consolidating the most up-to-date datasets available at the time of writing, along with examples of extreme events and progress in climate actions. The headlines in the State of the Climate Update 2024 give cause for great concern. Greenhouse gas concentrations continue to steadily rise, driving further long-term temperature increases, highlighting the rapid changes in our climate system in the space of a single generation. We are on track for 2024 to be the hottest year on record joining 2023 as the two hottest years on record. Ocean heat content values continued an upward trend in 2023 and 2024, contributing to other changes in the climate system such as sea level rise and fueling intense storms. Antarctic and Arctic sea ice extent in 2024 have both been well below average. The record-breaking rainfall and flooding, rapidly intensifying tropical cyclones, deadly heat, relentless drought and raging wildfires that we have seen in different parts of the world this year are unfortunately our new reality and a foretaste of our future. We must continue to strive to limit warming as much as possible, recognizing that staying well below 2°C above pre-industrial levels and pursuing efforts to limit warming to 1.5°C remains critical to significantly reduce the risks and impacts of climate change. At the same time, we need to step up support for climate change adaptation through climate services and early warnings

Regression From Prediabetes to Normal Glucose Regulation and Prevalence of Microvascular Disease in the Diabetes Prevention Program Outcomes Study (DPPOS)

OBJECTIVE Regression from prediabetes to normal glucose regulation (NGR) was associated with reduced incidence of diabetes by 56% over 10 years in participants in the Diabetes Prevention Program Outcomes Study (DPPOS). In an observational analysis, we examined whether regression to NGR also reduced risk for microvascular disease (MVD). RESEARCH DESIGN AND METHODS Generalized estimating equations were used to examine the prevalence of aggregate MVD at DPPOS year 11 in people who regressed to NGR at least once (vs. never) during the Diabetes Prevention Program (DPP). Logistic regression assessed the relationship of NGR with retinopathy, nephropathy, and neuropathy, individually. Generalized additive models fit smoothing splines to describe the relationship between average A1C during follow-up and MVD (and its subtypes) at the end of follow-up. RESULTS Regression to NGR was associated with lower prevalence of aggregate MVD in models adjusted for age, sex, race/ethnicity, baseline A1C, and treatment arm (odds ratio [OR] 0.78, 95% CI 0.65–0.78, P = 0.011). However, this association was lost in models that included average A1C during follow-up (OR 0.95, 95% CI 0.78–1.16, P = 0.63) or diabetes status at the end of follow-up (OR 0.92, 95% CI 0.75–1.12, P = 0.40). Similar results were observed in examination of the association between regression to NGR and prevalence of nephropathy and retinopathy, individually. Risk for aggregate MVD, nephropathy, and retinopathy increased across the A1C range. CONCLUSIONS Regression to NGR is associated with a lower prevalence of aggregate MVD, nephropathy, and retinopathy, primarily due to lower glycemic exposure over time. Differential risk for the MVD subtypes begins in the prediabetes A1C range. </jats:sec

Metabolite Profiles of Incident Diabetes and Heterogeneity of Treatment Effect in the Diabetes Prevention Program

Novel biomarkers of type 2 diabetes (T2D) and response to preventative treatment in individuals with similar clinical risk may highlight metabolic pathways that are important in disease development. We profiled 331 metabolites in 2,015 baseline plasma samples from the Diabetes Prevention Program (DPP). Cox models were used to determine associations between metabolites and incident T2D, as well as whether associations differed by treatment group (i.e., lifestyle [ILS], metformin [MET], or placebo [PLA]), over an average of 3.2 years of follow-up. We found 69 metabolites associated with incident T2D regardless of treatment randomization. In particular, cytosine was novel and associated with the lowest risk. In an exploratory analysis, 35 baseline metabolite associations with incident T2D differed across the treatment groups. Stratification by baseline levels of several of these metabolites, including specific phospholipids and AMP, modified the effect that ILS or MET had on diabetes development. Our findings highlight novel markers of diabetes risk and preventative treatment effect in individuals who are clinically at high risk and motivate further studies to validate these interactions.</jats:p

Long-term Effects of Metformin on Diabetes Prevention: Identification of Subgroups That Benefited Most in the Diabetes Prevention Program and Diabetes Prevention Program Outcomes Study

OBJECTIVE We examined the effects of metformin on diabetes prevention and the subgroups that benefited most over 15 years in the Diabetes Prevention Program (DPP) and its follow-up, the Diabetes Prevention Program Outcomes Study (DPPOS). RESEARCH DESIGN AND METHODS During the DPP (1996–2001), adults at high risk of developing diabetes were randomly assigned to masked placebo (n = 1,082) or metformin 850 mg twice daily (n = 1,073). Participants originally assigned to metformin continued to receive metformin, unmasked, in the DPPOS (2002–present). Ascertainment of diabetes development was based on fasting or 2-h glucose levels after an oral glucose tolerance test or on HbA1c. Reduction in diabetes incidence with metformin was compared with placebo in subgroups by hazard ratio (HR) and rate differences (RDs). RESULTS During 15 years of postrandomization follow-up, metformin reduced the incidence (by HR) of diabetes compared to placebo by 17% or 36% based on glucose or HbA1c levels, respectively. Metformin’s effect on the development of glucose-defined diabetes was greater for women with a history of prior gestational diabetes mellitus (GDM) (HR 0.59, RD −4.57 cases/100 person-years) compared with parous women without GDM (HR 0.94, RD −0.38 cases/100 person-years [interaction P = 0.03 for HR, P = 0.01 for RD]). Metformin also had greater effects, by HR and RD, at higher baseline fasting glucose levels. With diabetes development based on HbA1c, metformin was more effective in subjects with higher baseline HbA1c by RD, with metformin RD −1.03 cases/100 person-years with baseline HbA1c &amp;lt;6.0% (42 mmol/mol) and −3.88 cases/100 person-years with 6.0–6.4% (P = 0.0001). CONCLUSIONS Metformin reduces the development of diabetes over 15 years. The subsets that benefitted the most include subjects with higher baseline fasting glucose or HbA1c and women with a history of GDM. </jats:sec

Interaction Between Type 2 Diabetes Prevention Strategies and Genetic Determinants of Coronary Artery Disease on Cardiometabolic Risk Factors

Coronary artery disease (CAD) is more frequent among individuals with dysglycemia. Preventive interventions for diabetes can improve cardiometabolic risk factors (CRFs), but it is unclear whether the benefits on CRFs are similar for individuals at different genetic risk for CAD. We built a 201-variant polygenic risk score (PRS) for CAD and tested for interaction with diabetes prevention strategies on 1-year changes in CRFs in 2,658 Diabetes Prevention Program (DPP) participants. We also examined whether separate lifestyle behaviors interact with PRS and affect changes in CRFs in each intervention group. Participants in both the lifestyle and metformin interventions had greater improvement in the majority of recognized CRFs compared with placebo (P &amp;lt; 0.001) irrespective of CAD genetic risk (Pinteraction &amp;gt; 0.05). We detected nominal significant interactions between PRS and dietary quality and physical activity on 1-year change in BMI, fasting glucose, triglycerides, and HDL cholesterol in individuals randomized to metformin or placebo, but none of them achieved the multiple-testing correction for significance. This study confirms that diabetes preventive interventions improve CRFs regardless of CAD genetic risk and delivers hypothesis-generating data on the varying benefit of increasing physical activity and improving diet on intermediate cardiovascular risk factors depending on individual CAD genetic risk profile.</jats:p

The Impact of Physical Activity on the Prevention of Type 2 Diabetes: Evidence and Lessons Learned From the Diabetes Prevention Program, a Long-Standing Clinical Trial Incorporating Subjective and Objective Activity Measures

OBJECTIVE Across the Diabetes Prevention Program (DPP) follow-up, cumulative diabetes incidence remained lower in the lifestyle compared with the placebo and metformin randomized groups and could not be explained by weight. Collection of self-reported physical activity (PA) (yearly) with cross-sectional objective PA (in follow-up) allowed for examination of PA and its long-term impact on diabetes prevention. RESEARCH DESIGN AND METHODS Yearly self-reported PA and diabetes assessment and oral glucose tolerance test results (fasting glucose semiannually) were collected for 3,232 participants with one accelerometry assessment 11–13 years after randomization (n = 1,793). Mixed models determined PA differences across treatment groups. The association between PA and diabetes incidence was examined using Cox proportional hazards models. RESULTS There was a 6% decrease (Cox proportional hazard ratio 0.94 [95% CI 0.92, 0.96]; P &amp;lt; 0.001) in diabetes incidence per 6 MET-h/week increase in time-dependent PA for the entire cohort over an average of 12 years (controlled for age, sex, baseline PA, and weight). The effect of PA was greater (12% decrease) among participants less active at baseline (&amp;lt;7.5 MET-h/week) (n = 1,338) (0.88 [0.83, 0.93]; P &amp;lt; 0.0001), with stronger findings for lifestyle participants. Lifestyle had higher cumulative PA compared with metformin or placebo (P &amp;lt; 0.0001) and higher accelerometry total minutes per day measured during follow-up (P = 0.001 and 0.047). All associations remained significant with the addition of weight in the models. CONCLUSIONS PA was inversely related to incident diabetes in the entire cohort across the study, with cross-sectional accelerometry results supporting these findings. This highlights the importance of PA within lifestyle intervention efforts designed to prevent diabetes and urges health care providers to consider both PA and weight when counseling high-risk patients. </jats:sec

The Effect of Interventions to Prevent Type 2 Diabetes on the Development of Diabetic Retinopathy: The DPP/DPPOS Experience

OBJECTIVE To determine whether interventions that slow or prevent the development of type 2 diabetes in those at risk reduce the subsequent prevalence of diabetic retinopathy. RESEARCH DESIGN AND METHODS The Diabetes Prevention Program (DPP) randomized subjects at risk for developing type 2 diabetes because of overweight/obesity and dysglycemia to metformin (MET), intensive lifestyle intervention (ILS), or placebo (PLB) to assess the prevention of diabetes. During the DPP and DPP Outcome Study (DPPOS), we performed fundus photography over time on study participants, regardless of their diabetes status. Fundus photographs were graded using the Early Treatment Diabetic Retinopathy Study grading system, with diabetic retinopathy defined as typical lesions of diabetic retinopathy (microaneurysms, exudates, or hemorrhage, or worse) in either eye. RESULTS Despite reduced progression to diabetes in the ILS and MET groups compared with PLB, there was no difference in the prevalence of diabetic retinopathy between treatment groups after 1, 5, 11, or 16 years of follow-up. No treatment group differences in retinopathy were found within prespecified subgroups (baseline age, sex, race/ethnicity, baseline BMI). In addition, there was no difference in the prevalence of diabetic retinopathy between those exposed to metformin and those not exposed to metformin, regardless of treatment group assignment. CONCLUSIONS Interventions that delay or prevent the onset of type 2 diabetes in overweight/obese subjects with dysglycemia who are at risk for diabetes do not reduce the development of diabetic retinopathy for up to 20 years. </jats:sec